message: DOC: Improve docs for GraphMap.into_graph()
  This method has a panic case which was not documented. It's pretty
  straightforward, if the chosen index type is too small to hold the
  graph, it will panic.
diff: @@ -403,9 +403,15 @@ impl<N, E, Ty> GraphMap<N, E, Ty>
  /// Return a `Graph` that corresponds to this `GraphMap`.
  ///
  - /// Note: node and edge indices in the `Graph` have nothing in common
  - /// with the `GraphMap`s node weights `N`. The node weights `N` are
  - /// used as node weights in the resulting `Graph`, too.
  + /// 1. Note that node and edge indices in the `Graph` have nothing in common
  + /// with the `GraphMap`s node weights `N`. The node weights `N` are used as
  + /// node weights in the resulting `Graph`, too.
  + /// 2. Note that the index type is user-chosen.
  + ///
  + /// Computes in **O(|N| + |E|)** time (average).
  + ///
  + /// **Panics** if the number of nodes or edges does not fit with
  + /// the resulting graph's index type.
  pub fn into_graph<Ix>(self) -> Graph<N, E, Ty, Ix>
  where Ix: ::graph::IndexType,
  {
  