diff --git a/src/backend/concrete_environment.cc b/src/backend/concrete_environment.cc
index edb36ad..fa0ee6c 100644
--- a/src/backend/concrete_environment.cc
+++ b/src/backend/concrete_environment.cc
@@ -66,10 +66,10 @@ ConcreteEnvironment::ConcreteEnvironment(const ConcreteEnvironment& ce) :
 
 
 
-const Environment::ConstProcesses
+const Environment::Processes&
 ConcreteEnvironment::get_processes() const
 {
-  return ConstProcesses(_processes.begin(), _processes.end());
+  return _processes;
 }
 
 
@@ -82,10 +82,10 @@ ConcreteEnvironment::get_processes()
 
 
 
-const Environment::ConstResources
+const Environment::Resources&
 ConcreteEnvironment::get_resources() const
 {
-  return map<int, const Resource*>(_resources.begin(), _resources.end());
+  return _resources;
 }
 
 
@@ -98,10 +98,10 @@ ConcreteEnvironment::get_resources()
 
 
 
-const Environment::ConstRequests
+const Environment::Requests
 ConcreteEnvironment::get_request_queue(resource_key_t resource_key) const
 {
-  ConstRequests request_queue;
+  Requests request_queue;
 
 	typedef Processes::const_iterator  it1_t;
 
@@ -126,7 +126,7 @@ ConcreteEnvironment::get_request_queue(resource_key_t resource_key) const
 							const v4_t& subr = (*it3)->get_subrequests(); 
 							for(it4_t it4 = subr.begin(); it4 != subr.end(); it4++)
 								{
-									if((*it4)->get_resource() == resource_key) 
+									if((*it4)->get_resource_key() == resource_key) 
 										{
 											request_queue.push_back(*it3);
 											break;
diff --git a/src/backend/concrete_environment.hh b/src/backend/concrete_environment.hh
index a6ee378..d70903d 100644
--- a/src/backend/concrete_environment.hh
+++ b/src/backend/concrete_environment.hh
@@ -47,9 +47,6 @@ namespace sgpem
   {
 
   public:
-		typedef  std::vector<Process*>               Processes;
-		typedef  std::map<resource_key_t, Resource*> Resources;
-
     /// \brief Standard constructor.
     /// Builds an empty environment.
     ConcreteEnvironment();
@@ -69,7 +66,7 @@ namespace sgpem
     /// always safe.
     ///
     /// \return a constant set of snapshots of processes
-    virtual const ConstProcesses
+    virtual const Processes&
 			get_processes() const;
 
 
@@ -101,7 +98,7 @@ namespace sgpem
     ///
     /// \return a indexed constant set of snapshot of resources.
     /// \see DynamicSybrequest::get_resource()
-    virtual const ConstResources
+    virtual const Resources&
 			get_resources() const;
 
 
@@ -126,7 +123,7 @@ namespace sgpem
     ///
     /// \param resource The resource the requests are for
     /// \return The current ready requests queue.
-    virtual const ConstRequests
+    virtual const Requests
 			get_request_queue(resource_key_t resource_key) const;
 		
 		
diff --git a/src/backend/concrete_history.cc b/src/backend/concrete_history.cc
index bdb1c3f..8e20851 100644
--- a/src/backend/concrete_history.cc
+++ b/src/backend/concrete_history.cc
@@ -22,6 +22,12 @@
 
 #include "concrete_history.hh"
 
+#include "dynamic_process.hh"
+#include "dynamic_thread.hh"
+#include "dynamic_resource.hh"
+#include "dynamic_request.hh"
+#include "dynamic_sub_request.hh"
+
 #include "static_process.hh"
 #include "static_thread.hh"
 #include "static_resource.hh"
@@ -38,6 +44,40 @@ using namespace sgpem;
 using namespace std;
 using memory::smart_ptr;
 
+
+// ---------------
+// For all your evil-doers on Earth, this is your punishment!
+
+template<typename T>
+static bool deep_remove(std::vector<T*>& v, const T& obj)
+{
+	typedef typename std::vector<T*> Vector;
+	for(typename Vector::iterator it = v.begin(); it != v.end(); it++)
+		if(**it == obj)
+			{
+				delete *it;
+				v.erase(it);
+				return true;
+			}
+	return false;
+}
+
+
+template<typename T>
+static T* deep_find(const std::vector<T*>& v, const T& obj)
+{
+	typedef typename std::vector<T*> Vector;
+	for(typename Vector::const_iterator it = v.begin(); it != v.end(); it++)
+		if(**it == obj)
+			{
+				return *it;
+			}
+	return NULL;
+}
+
+
+// -----------------
+
 ConcreteHistory::ConcreteHistory()
 	: History(), _snapshots()
 {
@@ -85,23 +125,18 @@ ConcreteHistory::get_environment_at(position index) const
 void  
 ConcreteHistory::remove(resource_key_t resource_key)
 {
+	// Pay attention that initial isn't deleted by reset()
 	ConcreteEnvironment& initial = *_snapshots.front();
 	ConcreteEnvironment::Resources& resources = initial.get_resources();
 	ConcreteEnvironment::Resources::iterator found = resources.find(resource_key);
-	if(found == resources.end())		
-		{
-			notify_change();
-			return; // not found, just return. Can we do this better (without a reset)?
-		}
+	if(found == resources.end())
+		return;
 
 	reset(false);
 
-	// FIXME: I'm really tired, check that the next two lines do 
-	// what they're meant to do!
 	delete found->second;
 	resources.erase(found);
 
-
 #warning "write me!"
 	// FIXME write me	: check for subrequests to remove
 
@@ -110,47 +145,92 @@ ConcreteHistory::remove(resource_key_t resource_key)
 
 
 void
-ConcreteHistory::remove(const Process& process)
+ConcreteHistory::remove(Process& process)
 {
-
-	reset(false);
-	
+	// Pay attention that initial isn't deleted by reset()
 	ConcreteEnvironment& initial = *_snapshots.front();
 	ConcreteEnvironment::Processes& processes = initial.get_processes();
-	ConcreteEnvironment::Processes::iterator found = find(processes.begin(), processes.end(), &process);
-	if(found == processes.end()) 
-		{
-			notify_change();
-			return; // not found, just return. Can we do this better (without a reset)?
-		}
-
-	// FIXME: I'm really tired, check that the next two lines do 
-	// what they're meant to do!
-	delete *found;
-	processes.erase(found);
-
-	notify_change();
+	bool found = deep_remove<Process>(processes, process);
+	if(found) 
+		reset(true);
 }
 
 
 void  
-ConcreteHistory::remove(const Thread& thread)
+ConcreteHistory::remove(Thread& thread)
 {
-#warning "write me!"
+	DynamicThread&  dyn_thr  = dynamic_cast<DynamicThread&>(thread);
+
+	// Pay attention that initial isn't deleted by reset()
+	ConcreteEnvironment& initial = *_snapshots.front();
+	ConcreteEnvironment::Processes& processes = initial.get_processes();
+
+  Process* found = deep_find<Process>(processes, dyn_thr.get_process());
+
+	if(found == NULL) 
+		return; // not found, just return.
+	
+	DynamicProcess& dynamic_found = dynamic_cast<DynamicProcess&>(*found);
+	bool removed = deep_remove<DynamicThread>(dynamic_found.get_dynamic_threads(), dyn_thr);
+
+	if(removed)
+		reset(true);
 }
 	
 
 void
-ConcreteHistory::remove(const Request& request)
+ConcreteHistory::remove(Request& request)
 {
-#warning "write me!"
+	DynamicRequest&  dyn_req  = dynamic_cast<DynamicRequest&>(request);
+	DynamicThread&   dyn_thr  = dyn_req.get_thread();
+	DynamicProcess&  dyn_proc = dyn_thr.get_process();
+
+	// Pay attention that initial isn't deleted by reset()
+	ConcreteEnvironment& initial = *_snapshots.front();
+	ConcreteEnvironment::Processes& processes = initial.get_processes();
+
+  Process* proc_ref = deep_find<Process>(processes, dyn_proc);
+	DynamicProcess* dyn_proc_ref = dynamic_cast<DynamicProcess*>(proc_ref);
+	if(dyn_proc_ref == NULL) 
+		return; // not found, just return.
+	DynamicThread*  thr_ref  = deep_find<DynamicThread>(dyn_proc_ref->get_dynamic_threads(), dyn_thr);
+	if(thr_ref == NULL)
+		return; // not found, just return.
+
+	bool removed = deep_remove<DynamicRequest>(thr_ref->get_dynamic_requests(), dyn_req);
+
+	if(removed)
+		reset(true);
 }
 
 
 void  
-ConcreteHistory::remove(const SubRequest& subrequest)
+ConcreteHistory::remove(SubRequest& subrequest)
 {
-#warning "write me!"
+	DynamicSubRequest& dyn_sub  = dynamic_cast<DynamicSubRequest&>(subrequest);
+	DynamicRequest&    dyn_req  = dyn_sub.get_request();
+	DynamicThread&     dyn_thr  = dyn_req.get_thread();
+	DynamicProcess&    dyn_proc = dyn_thr.get_process();
+
+	// Pay attention that initial isn't deleted by reset()
+	ConcreteEnvironment& initial = *_snapshots.front();
+	ConcreteEnvironment::Processes& processes = initial.get_processes();
+
+  Process* proc_ref = deep_find<Process>(processes, dyn_proc);
+	DynamicProcess* dyn_proc_ref = dynamic_cast<DynamicProcess*>(proc_ref);
+	if(dyn_proc_ref == NULL) 
+		return; // not found, just return.
+	DynamicThread*  thr_ref  = deep_find<DynamicThread>(dyn_proc_ref->get_dynamic_threads(), dyn_thr);
+	if(thr_ref == NULL)
+		return; // not found, just return.
+	DynamicRequest*  req_ref  = deep_find<DynamicRequest>(thr_ref->get_dynamic_requests(), dyn_req);
+	if(req_ref == NULL)
+		return; // not found, just return.
+
+	bool removed = deep_remove<DynamicSubRequest>(req_ref->get_dynamic_subrequests(), dyn_sub);
+
+	if(removed)
+		reset(true);
 }
 
 
@@ -160,7 +240,17 @@ ConcreteHistory::add_resource(const Glib::ustring& name,
 															size_t places,
 															size_t availability)
 {
-	#warning "write me!"
+	reset(false);
+
+	// And preemptable and availability?? FIXME!
+
+	StaticResource* core = new StaticResource(name, places);
+	DynamicResource* resource = new DynamicResource(core);
+
+#warning "write me! insert into map and get iterator in an efficient way."
+
+	notify_change();
+		
 }
 
 
@@ -178,6 +268,7 @@ ConcreteHistory::add_process(const Glib::ustring& name,
 	processes.push_back(proc);
 
 	notify_change();
+	return *proc;
 }
 
 
@@ -192,11 +283,12 @@ ConcreteHistory::add_thread(const Glib::ustring& name,
 	
 	// Holy cow! *THIS* is ugly!!!!
 	DynamicProcess& parent_process = dynamic_cast<DynamicProcess&>(parent);
-	StaticProcess& parent_core = parent_process.get_core();
-	StaticThread* core = new StaticThread(name, parent_core, cpu_time, arrival_time, base_priority);
-	DynamicThread* thread = new DynamicThread(core, &parent_process);
+	StaticProcess&  parent_core    = parent_process.get_core();
+	StaticThread*   core   = new StaticThread(name, parent_core, cpu_time, arrival_time, base_priority);
+	DynamicThread*  thread = new DynamicThread(core, &parent_process);
 	
 	notify_change();
+	return *thread;
 }
 
 
@@ -204,7 +296,18 @@ DynamicRequest&
 ConcreteHistory::add_request(Thread& owner,
 														 time_t instant)
 {
-#warning "write me!"
+	reset(false);
+	
+	DynamicThread& dyn_owner = dynamic_cast<DynamicThread&>(owner);
+	StaticThread&  owner_core = dyn_owner.get_core();
+	
+	StaticRequest* core = new StaticRequest(&owner_core, instant);
+	DynamicRequest* req = new DynamicRequest(core, &dyn_owner);
+
+	dyn_owner.get_requests().push_back(req);
+
+	notify_change();
+	return *req;
 }
 
 
@@ -214,25 +317,30 @@ ConcreteHistory::add_subrequest(Request& request,
 																time_t  duration,
 																size_t  places)
 {
-#warning "write me!"
+	reset(false);
+	
+ 	DynamicRequest& dyn_request = dynamic_cast<DynamicRequest&>(request);
+	StaticRequest&  request_core = dyn_request.get_core();
+	
+	StaticSubRequest* core = new StaticSubRequest(&request_core, resource_key, duration, places);
+	DynamicSubRequest* subreq = new DynamicSubRequest(core, &dyn_request);
+
+	dyn_request.get_subrequests().push_back(subreq);
+
+	notify_change();
+	return *subreq;
 }
 
 
 void
 ConcreteHistory::reset(bool notify)
 {
+	assert(_snapshots.size() > 0);
 	Snapshots::iterator it = _snapshots.begin();
-	ConcreteEnvironment* model = *it;
-
 	it++; // Skip first environment that we saved
+	
 	for_each(it, _snapshots.end(), ptr_fun(operator delete));
-	_snapshots.clear();
-	_snapshots.push_back(new ConcreteEnvironment());
-
-	// FIXME write code to copy processes and threads and subrequests......
-#warning "write me!"
-
-	delete model;
+	_snapshots.resize(1); // Truncate to keep only our "model"
 
 	if(notify)
 		notify_change();
diff --git a/src/backend/concrete_history.hh b/src/backend/concrete_history.hh
index 9f0b9f6..0c83a63 100644
--- a/src/backend/concrete_history.hh
+++ b/src/backend/concrete_history.hh
@@ -57,10 +57,10 @@ namespace sgpem
 		virtual const ConcreteEnvironment& get_environment_at(position index) const throw(std::out_of_range);
 		
 		virtual void  remove(resource_key_t resource_key);
-		virtual void  remove(const Process&    process);
-		virtual void  remove(const Thread&     thread);
-		virtual void  remove(const Request&    request);
-		virtual void  remove(const SubRequest& subrequest);
+		virtual void  remove(Process&    process);
+		virtual void  remove(Thread&     thread);
+		virtual void  remove(Request&    request);
+		virtual void  remove(SubRequest& subrequest);
 
 
 		virtual ResourcePair&       add_resource(const Glib::ustring& name,
diff --git a/src/backend/dynamic_request.cc b/src/backend/dynamic_request.cc
index 0bbcf1a..5c7dd62 100644
--- a/src/backend/dynamic_request.cc
+++ b/src/backend/dynamic_request.cc
@@ -45,10 +45,6 @@ DynamicRequest::DynamicRequest(StaticRequest *core,
 
 DynamicRequest::~DynamicRequest()
 {
-	typedef std::vector<DynamicRequest*> Requests;
-	Requests& siblings = _dynamic_thread->get_dynamic_requests();
-	siblings.erase(find(siblings.begin(), siblings.end(), this));
-
 	for_each(_dynamic_subrequests.begin(), _dynamic_subrequests.end(), ptr_fun(operator delete));
 }
 
diff --git a/src/backend/dynamic_sub_request.cc b/src/backend/dynamic_sub_request.cc
index aedd9ae..274ab43 100644
--- a/src/backend/dynamic_sub_request.cc
+++ b/src/backend/dynamic_sub_request.cc
@@ -29,9 +29,8 @@
 using namespace sgpem;
 
 DynamicSubRequest::DynamicSubRequest(StaticSubRequest* core, 
-																		 DynamicRequest* owner,
-																		 resource_key_t key) :
-	_static_subrequest(core), _owner(owner), _resource_key(key),
+																		 DynamicRequest* owner) :
+	_static_subrequest(core), _owner(owner),
 	_queue_position(-1)
 {
   assert(core != NULL);
@@ -41,9 +40,6 @@ DynamicSubRequest::DynamicSubRequest(StaticSubRequest* core,
 
 DynamicSubRequest::~DynamicSubRequest()
 {
-	typedef std::vector<DynamicSubRequest*> SubRequests;
-	SubRequests& siblings = _owner->get_dynamic_subrequests();
-	siblings.erase(find(siblings.begin(), siblings.end(), this));
 }
 
 
@@ -58,7 +54,7 @@ DynamicSubRequest::operator==(const SubRequest& op2) const
 SubRequest::resource_key_t
 DynamicSubRequest::get_resource_key() const
 {
-  return _resource_key;
+  return _static_subrequest->get_resource_key();
 }
 
 unsigned int
@@ -85,6 +81,14 @@ DynamicSubRequest::set_queue_position(int position)
   _queue_position = position;
 }
 
+
+DynamicRequest&
+DynamicSubRequest::get_request()
+{
+	return *_owner;
+}
+
+
 void
 DynamicSubRequest::serialize(SerializeVisitor& translator) const
 {
diff --git a/src/backend/dynamic_sub_request.hh b/src/backend/dynamic_sub_request.hh
index fc6f6a1..0e5ba34 100644
--- a/src/backend/dynamic_sub_request.hh
+++ b/src/backend/dynamic_sub_request.hh
@@ -23,6 +23,7 @@
 
 #include "config.h"
 #include "sub_request.hh"
+#include "dynamic_request.hh"
 #include "dynamic_resource.hh"
 #include "static_sub_request.hh"
 
@@ -31,7 +32,6 @@
 namespace sgpem
 {
   class DynamicSubRequest;
-	class DynamicRequest;
 	class SerializeVisitor;
   class Resource;
   class StaticSubRequest;
@@ -40,8 +40,7 @@ namespace sgpem
   {
   public:
     DynamicSubRequest(StaticSubRequest* core, 
-											DynamicRequest* owner,
-											resource_key_t resource);
+											DynamicRequest* owner);
 
 		virtual ~DynamicSubRequest();
 
@@ -56,6 +55,8 @@ namespace sgpem
     int get_queue_position() const;
     void set_queue_position(int position);
 
+		virtual DynamicRequest& get_request();
+
     void serialize(SerializeVisitor& translator) const;
 
 		StaticSubRequest& get_core();
@@ -64,11 +65,9 @@ namespace sgpem
   private:
     memory::smart_ptr<StaticSubRequest> _static_subrequest;
 		DynamicRequest*  _owner;
-    resource_key_t   _resource_key;
     int              _queue_position;
   };
 
 }
 
 #endif
-
diff --git a/src/backend/dynamic_thread.cc b/src/backend/dynamic_thread.cc
index 5f11780..8de5736 100644
--- a/src/backend/dynamic_thread.cc
+++ b/src/backend/dynamic_thread.cc
@@ -54,10 +54,6 @@ DynamicThread::DynamicThread(const DynamicThread &other) :
 
 DynamicThread::~DynamicThread()
 {
-	typedef std::vector<DynamicThread*> Threads;
-	Threads& siblings = _parent->get_dynamic_threads();
-	siblings.erase(find(siblings.begin(), siblings.end(), this));
-
 	for_each(_dynamic_requests.begin(), _dynamic_requests.end(), ptr_fun(operator delete));
 }
 
diff --git a/src/backend/environment.hh b/src/backend/environment.hh
index 49ed66b..b4dc8d8 100644
--- a/src/backend/environment.hh
+++ b/src/backend/environment.hh
@@ -60,9 +60,9 @@ namespace sgpem
   public:
 		typedef SubRequest::resource_key_t     resource_key_t;
 
-		typedef std::vector<const Process*>    ConstProcesses;
-		typedef std::map<resource_key_t, const Resource*> ConstResources; 
-		typedef std::vector<const Request*>    ConstRequests;
+		typedef std::vector<Process*>    Processes;
+		typedef std::map<resource_key_t, Resource*> Resources; 
+		typedef std::vector<Request*>    Requests;
 
     /// \brief Returns an indexed set of snapshots of the processes
     /// Returns a standard vector of Process objects describing
@@ -71,7 +71,7 @@ namespace sgpem
     ///
     /// \return a constant set of snapshots of processes
 
-    virtual const ConstProcesses
+    virtual const Processes&
 			get_processes() const = 0;
 
 
@@ -89,7 +89,7 @@ namespace sgpem
     ///
     /// \return an indexed constant set of snapshot of resources.
 
-    virtual const ConstResources
+    virtual const Resources&
 			get_resources() const = 0;
 
 
@@ -100,7 +100,7 @@ namespace sgpem
     /// \param resource the resource the requests are for
     /// \return the current ready requests queue (constant).
 
-    virtual const ConstRequests
+    virtual const Requests
 			get_request_queue(resource_key_t resource_key) const = 0;
 
 
diff --git a/src/backend/history.hh b/src/backend/history.hh
index 52bd765..f157b3b 100644
--- a/src/backend/history.hh
+++ b/src/backend/history.hh
@@ -71,10 +71,10 @@ namespace sgpem
 		virtual const Environment& get_environment_at() const throw(std::out_of_range) = 0;
 		
 		virtual void  remove(resource_key_t resource_key)  = 0;
-		virtual void  remove(const Process&    process)    = 0;
-		virtual void  remove(const Thread&     thread)     = 0;
-		virtual void  remove(const Request&    request)    = 0;
-		virtual void  remove(const SubRequest& subrequest) = 0;
+		virtual void  remove(Process&    process)          = 0;
+		virtual void  remove(Thread&     thread)           = 0;
+		virtual void  remove(Request&    request)          = 0;
+		virtual void  remove(SubRequest& subrequest)       = 0;
 
 
 		virtual ResourcePair& add_resource(const Glib::ustring& name,
diff --git a/src/backend/static_sub_request.cc b/src/backend/static_sub_request.cc
index f9fcabf..e09d145 100644
--- a/src/backend/static_sub_request.cc
+++ b/src/backend/static_sub_request.cc
@@ -27,10 +27,10 @@
 using namespace sgpem;
 
 StaticSubRequest::StaticSubRequest(StaticRequest* req,
-                                   StaticResource* resource,
+                                   resource_key_t resource_key,
                                    unsigned int length,
                                    unsigned int places) :
-    _static_request(req), _static_resource(resource),
+    _static_request(req), _resource_key(resource_key),
     _length(length), _places(places)
 {
   assert(req != NULL && resource != NULL);
@@ -42,13 +42,13 @@ StaticSubRequest::~StaticSubRequest()
 {
 	typedef std::vector<StaticSubRequest*> SubRequests;
 	SubRequests siblings& = _static_request.get_subrequests();
-	siblings.erase(find(siblings.begin(), siblings.end(), this);
+	siblings.erase(find(siblings.begin(), siblings.end(), this));
 }
 
-StaticResource&
-StaticSubRequest::get_static_resource()
+SubRequest::get_resource_key
+StaticSubRequest::get_resource_key() const
 {
-  return *_static_resource;
+  return _resource_key;
 }
 
 StaticRequest&
diff --git a/src/backend/static_sub_request.hh b/src/backend/static_sub_request.hh
index 3466193..83efefa 100644
--- a/src/backend/static_sub_request.hh
+++ b/src/backend/static_sub_request.hh
@@ -23,6 +23,8 @@
 
 #include "config.h"
 
+#include "sub_request.hh"
+
 namespace sgpem
 {
   class StaticSubRequest;
@@ -32,16 +34,18 @@ namespace sgpem
   class SG_DLLLOCAL StaticSubRequest
   {
   public:
+		typedef SubRequest::resource_key_t resource_key_t;
+
     StaticSubRequest(StaticRequest* req,
-                     StaticResource* resource,
+                     resource_key_t resource_key,
                      unsigned int length,
                      unsigned int places = 1);
 
 		virtual ~StaticSubRequest();
 
-    StaticResource& get_static_resource();
+    resource_key_t get_resource_key() const;
 
-    StaticRequest& get_static_request();
+    StaticRequest& get_request();
 
     unsigned int get_places() const;
 
@@ -49,9 +53,10 @@ namespace sgpem
 
   private:
     StaticSubRequest(const StaticSubRequest&);
+		StaticSubRequest& operator=(const StaticSubRequest&);
 
     StaticRequest* _static_request;
-    StaticResource* _static_resource;
+    resource_key_t _resource_key;
     unsigned int _length;
     unsigned int _places;
   };
diff --git a/src/backend/sub_request.hh b/src/backend/sub_request.hh
index 358fc0c..38a3aa1 100644
--- a/src/backend/sub_request.hh
+++ b/src/backend/sub_request.hh
@@ -27,6 +27,7 @@ namespace sgpem
 {
   class SubRequest;
   class SerializeVisitor;
+	class Request;
   class Resource;
 
   class SG_DLLEXPORT SubRequest
@@ -38,7 +39,7 @@ namespace sgpem
 
 		virtual bool operator==(const SubRequest& op2) const = 0;
 
-    virtual resource_key_t get_resource() = 0;
+    virtual resource_key_t get_resource_key() const = 0;
 
     virtual unsigned int   get_places() const = 0;
 
@@ -46,6 +47,8 @@ namespace sgpem
 
     virtual int get_queue_position() const = 0;
 
+		virtual Request& get_request() = 0;
+
     virtual void serialize(SerializeVisitor& translator) const = 0;
   };