def _first_unvisited(graph, visited):
    """
    Return first unvisited node.
    
    @type  graph: graph
    @param graph: Graph.

    @type  visited: list
    @param visited: List of nodes.
    
    @rtype:  node
    @return: First unvisited node.
    """
    for each in graph:
        if (each not in visited):
            return each
    return None
dataset/ETHPy150Open pmatiello/python-graph/core/pygraph/algorithms/minmax.py/_first_unvisited/original