module documentation
        
        Undocumented
| Function | _add | Undocumented | 
| Function | _graphmethod | Auxiliary decorator | 
Auxiliary decorator
This decorator allows some methods of VertexSeq and EdgeSeq to call their respective counterparts in Graph to avoid code duplication.
| Parameters | |
| func | the function being decorated. This function will be called on the results of the original Graphmethod. If None, defaults to the identity function. | 
| name | the name of the corresponding method in Graph. If None, it defaults to the name of the decorated function. | 
| Returns | |
| the decorated function | |