code: def get_nodes_list_by_process_id(self, process_id):
          
          tmp_nodes = self.diagram_graph.nodes(True)
          nodes = []
          for node in tmp_nodes:
              if node[1][consts.Consts.process] == process_id:
                  nodes.append(node)
          return nodes
docs: Gets all nodes of requested type. If no type is provided by user, all nodes in BPMN diagram graph are returned.
          Returns a dictionary, where key is an ID of node, value is a dictionary of all node attributes.
  
          :param process_id: string object, representing an ID of parent process element.