code: def createGraph(self, name, createCollections = True, isSmart = False, numberOfShards = None, smartGraphAttribute = None) :
          
  
          def _checkCollectionList(lst) :
              for colName in lst :
                  if not COL.isCollection(colName) :
                      raise ValueError("'%s' is not a defined Collection" % colName)
  
          graphClass = GR.getGraphClass(name)
  
          ed = []
          for e in graphClass._edgeDefinitions :
              if not COL.isEdgeCollection(e.edgesCollection) :
                  raise ValueError("'%s' is not a defined Edge Collection" % e.edgesCollection)
              _checkCollectionList(e.fromCollections)
              _checkCollectionList(e.toCollections)
  
              ed.append(e.toJson())
  
          _checkCollectionList(graphClass._orphanedCollections)
  
          options = {}
          if numberOfShards:
              options['numberOfShards'] = numberOfShards
          if smartGraphAttribute:
              options['smartGraphAttribute'] = smartGraphAttribute
  
          payload = {
                  "name": name,
                  "edgeDefinitions": ed,
                  "orphanCollections": graphClass._orphanedCollections
              }
  
          if isSmart :
                  payload['isSmart'] = isSmart
  
          if options:
              payload['options'] = options
  
          payload = json.dumps(payload)
  
          r = self.connection.session.post(self.graphsURL, data = payload)
          data = r.json()
  
          if r.status_code == 201 or r.status_code == 202 :
              self.graphs[name] = graphClass(self, data["graph"])
          else :
              raise CreationError(data["errorMessage"], data)
          return self.graphs[name]
docs: Creates a graph and returns it. 'name' must be the name of a class inheriting from Graph.
          Checks will be performed to make sure that every collection mentionned in the edges definition exist. Raises a ValueError in case of
          a non-existing collection.