'return field metadata from the object if it is there. Otherwise return
None. field is the key name, not the label. Return a copy if requested,
just in case the user wants to change values in the dict.'

def get_user_metadata(self, field, make_copy):

    _data = object.__getattribute__(self, '_data')
    _data = _data['user_metadata']
    if (field in _data):
        if make_copy:
            return copy.deepcopy(_data[field])
        return _data[field]
    return None
