Function find_augmenting_path 

fn find_augmenting_path<G>(
    network: G,
    source: G::NodeId,
    destination: G::NodeId,
    flows: &[G::EdgeWeight],
    level_edges: &mut [Vec<G::EdgeRef>],
    visited: &mut G::Map,
    edge_to: &mut [Option<G::EdgeRef>],
) -> bool
where
    G: IntoEdges + NodeIndexable + EdgeIndexable + Visitable,
    G::EdgeWeight: Sub<Output = G::EdgeWeight> + PositiveMeasure,

Makes a DFS to find an augmenting path from source to destination vertex using previously computed edge_levels from level graph.

Returns a boolean indicating if an augmenting path to destination was found.