XYZ: Allow multiple objects at same position

sandbox/engulf/simulation.py

 
         if isinstance(value, Cell):
             try:
-                del self.cell_xyz[value.position]
-            except KeyError:
-                pass  # TODO: cE DICT DOIT CONTENIR DES LISTES DE SUBJECTS
+                self.cell_xyz.get(value.position, []).remove(value)
+            except ValueError:
+                pass
 
         if isinstance(value, Grass):
             del self.grass_xyz[value.position]
         super().append(p_object)
 
         if isinstance(p_object, Cell):
-            self.cell_xyz[p_object.position] = p_object
+            self.cell_xyz.get(p_object.position, []).append(p_object)
 
         if isinstance(p_object, Grass):
-            self.grass_xyz[p_object.position] = p_object
+            self.grass_xyz.get(p_object.position, []).append(p_object)
 
 
 class Engulf(XYZSimulation):

synergine2/xyz.py

         super().remove(value)
 
         try:
-            del self.xyz[value.position]
-        except KeyError:
-            pass  # TODO: cE DICT DOIT CONTENIR DES LISTES DE SUBJECTS
+            self.xyz.get(value.position, []).remove(value)
+        except ValueError:
+            pass
 
     def append(self, p_object: XYZSubjectMixin):
         super().append(p_object)
                 str(p_object),
             ))
 
-        self.xyz[p_object.position] = p_object
+        self.xyz.get(p_object.position, []).append(p_object)
 
 
 class XYZSimulation(BaseSimulation):