Function subgraph_isomorphisms 

pub fn subgraph_isomorphisms<P, T, N, E>(
    pattern: &P,
    target: &T,
    mode: SubgraphMode,
    max_mappings: usize,
    node_match: N,
    edge_match: E,
) -> IsomorphismSearch<P::Node, T::Node>
where
    P: IndexGraphView,
    T: IndexGraphView,
    N: Fn(P::Node, T::Node) -> bool,
    E: Fn(P::Edge, T::Edge) -> bool,