(self)
Returns True if this cursor is still active, that is it has not
        read past the last arc in the graph.
Returns True if this cursor is still active, that is it has not
        read past the last arc in the graph.
Returns True if this cursor is still active that is it has not read past the last arc in the graph .
def is_active(self):
        """Returns True if this cursor is still active, that is it has not
        read past the last arc in the graph.
        """

        raise NotImplementedError
def is_active ( self ) : raise NotImplementedError