def add_external_node(self, external_node_name, jump_into_node_begin, jump_into_node_function, external_node_description=None):
    'Adds an external node to the graph. Required input is node_name (a string with no spaces),\n        a reference to an entering node,the function mapping the entering node to the new external node'
    self.external_node_names.append(external_node_name)
    self.add_jump(begin_node=jump_into_node_begin, end_node=external_node_name, jump_function=jump_into_node_function)
    if external_node_description:
        self.external_node_descriptions.append(external_node_description)
    self.display_graph.add_node(external_node_name)
    self.display_graph.add_edge(jump_into_node_begin, external_node_name)
    self.display_layout = networkx.spring_layout(self.display_graph)
Adds an external node to the graph. Required input is node_name (a string with no spaces),
a reference to an entering node,the function mapping the entering node to the new external node
def add_external_node(self, external_node_name, jump_into_node_begin, jump_into_node_function, external_node_description=None):
    'Adds an external node to the graph. Required input is node_name (a string with no spaces),\n        a reference to an entering node,the function mapping the entering node to the new external node'
    self.external_node_names.append(external_node_name)
    self.add_jump(begin_node=jump_into_node_begin, end_node=external_node_name, jump_function=jump_into_node_function)
    if external_node_description:
        self.external_node_descriptions.append(external_node_description)
    self.display_graph.add_node(external_node_name)
    self.display_graph.add_edge(jump_into_node_begin, external_node_name)
    self.display_layout = networkx.spring_layout(self.display_graph)