<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def set_edge_label(self, edge, label):
 """ Set the label of an edge. @type edge: edge @param edge: One edge. @type label: string @param label: Edge label. """

        self.set_edge_properties(edge, label=label )
        if not self.DIRECTED:
            self.set_edge_properties((edge[1], edge[0]) , label=label )