def add_node(self, graph_node):
if not isinstance(graph_node, Node):<EOL><INDENT>raise TypeError('<STR_LIT>' + str(graph_node))<EOL><DEDENT>node = self.get_node(graph_node.get_name())<EOL>if not node:<EOL><INDENT>self.obj_dict['<STR_LIT>'][graph_node.get_name()] = [ graph_node.obj_dict ]<EOL>graph_node.set_parent_graph(self.get_parent_graph())<EOL><DEDENT>else:<EOL><INDENT>self.obj_dict['<STR_LIT>'][graph_node.get_name()].append( graph_node.obj_dict )<EOL><DEDENT>graph_node.set_sequence(self.get_next_sequence_number())<EOL>
Adds a node object to the graph.

        It takes a node object as its only argument and returns
        None.