def get_cell_boundary_variables(ds):
    '''
    Returns a list of variable names for variables that represent cell
    boundaries through the `bounds` attribute

    :param netCDF4.Dataset nc: netCDF dataset
    '''
    boundary_variables = []
    has_bounds = ds.get_variables_by_attributes(bounds=lambda x: x is not None)
    for var in has_bounds:
        if var.bounds in ds.variables:
            boundary_variables.append(var.bounds)
    return boundary_variables
Returns a list of variable names for variables that represent cell
    boundaries through the `bounds` attribute

    :param netCDF4.Dataset nc: netCDF dataset