def unique_trees(msts):
    """
    Test whether a list of minimum spanning trees are unique.

    Args:
        msts (list, nx.Graph): list of minimum spanning trees.

    Returns:
        (boolean): whether all trees in the list are unique.
    """
    for i, mst1 in enumerate(msts):
        for j, mst2 in enumerate(msts):
            if i != j:
                mst1_edges = set(mst1.edges)
                mst2_edges = set(mst2.edges)
                if len(mst1_edges.difference(mst2_edges)) == 0:
                    return False
    return True