def METHOD_NAME(residualGraph, parent, source, sink):
    visited = [False] * len(residualGraph)
    queue = deque()
    queue.append(source)
    visited[source] = True
    parent[source] = None
    while queue:
        u = queue.popleft()
        for edge in residualGraph[u]:
            v = edge.v
            if not visited[v] and edge.capacity > edge.flow:
                queue.append(v)
                visited[v] = True
                parent[v] = u
    return visited[sink]