Function has_path_connecting 

pub fn has_path_connecting<G>(
    g: G,
    from: G::NodeId,
    to: G::NodeId,
    space: Option<&mut DfsSpace<G::NodeId, G::Map>>,
) -> bool
where
    G: IntoNeighbors + Visitable,

Check if there exists a path starting at from and reaching to.

If from and to are equal, this function returns true.

Arguments:

• g: an input graph.
• from: the first node of a desired path.
• to: the last node of a desired path.
• space: optional DfsSpace. If space is not None, it is used instead of creating a new workspace for graph traversal.

Returns

• true: if there exists a path starting at from and reaching to or from and to are equal.
• false: otherwise.

Complexity

• Time complexity: O(|V| + |E|).
• Auxiliary space: O(|V|) or O(1) if space was provided.

where |V| is the number of nodes and |E| is the number of edges.