message: DOC: Add doc for StableGraph::filter_map
diff: @@ -761,6 +761,17 @@ impl<N, E, Ty, Ix> StableGraph<N, E, Ty, Ix>
  }
  }
  + /// Create a new `StableGraph` by mapping nodes and edges.
  + /// A node or edge may be mapped to `None` to exclude it from
  + /// the resulting graph.
  + ///
  + /// Nodes are mapped first with the `node_map` closure, then
  + /// `edge_map` is called for the edges that have not had any endpoint
  + /// removed.
  + ///
  + /// The resulting graph has the structure of a subgraph of the original graph.
  + /// Nodes and edges that are not removed maintain their old node or edge
  + /// indices.
  pub fn filter_map<'a, F, G, N2, E2>(&'a self, mut node_map: F, mut edge_map: G)
  -> StableGraph<N2, E2, Ty, Ix>
  where F: FnMut(NodeIndex<Ix>, &'a N) -> Option<N2>,
  