def CreateEmptyHubDictionary(input_map):
    """hub_map_tools.CreateEmptyHubDictionary()
    INPUTS:
    - input_map  -- a hub map dictionary with teacher or grade name keys, and
                    hub IDs for values
    OUTPUTS:
    - output_map -- a new dictionary keyed by unique hub IDs, and having
                    empty lists for values.
    ASSUMPTONS:
    - none
    """
    new_keys = list(input_map.values())
    i = 0
    while i < len(new_keys)-1:
        while new_keys.count( new_keys[i] ) > 1:
            new_keys.pop( new_keys.index( new_keys[i], i+1 ) )
        i+=1

    output_map = {}
    for key in new_keys:
        output_map[key] = []
    return output_map