def skeleton_cell(ske_crack, pos_busbar):
    """Get the skeleton of a cell. Crack has the value of -1, busbar is 1, other area is 0.
    Parameters
    ----------
    ske_crack: array
    Skeleton of crack masks

    pos_busbar: list
    Position of busbars

    Returns
    -------
    ske_cell: array
    Skeleton of cell
    """
    ske_cell = ske_crack * -1
    for i in pos_busbar:
        ske_cell[i, :] = 1

    return ske_cell