def pair_uv_to_hf(network, volmesh):
    """Pairs the directed edges (u, v) of a network to the corresponding halffaces of the dual volmesh.

    Parameters
    ----------
    volmesh : VolMesh
        A volmesh object representing a polyhedral force diagram.
    network : Network
        A network object representing a polyhedral form diagram.

    Returns
    -------
    dictionary
        A dictionary of (u, v)-u_hfkey pairs.

    """
    uv_hf_dict = {}
    for u, v in network.edges():
        u_hfkey, v_hfkey = volmesh.cell_pair_halffaces(u, v)
        uv_hf_dict[u, v] = u_hfkey
    return uv_hf_dict
