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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _get_filter_modifier(self, field):
 """Detect the filter modifier"""

        tokens = field.split(FIELD_SEPARATOR)
        if len(tokens) == 1:
            return field, ""
        if tokens[-1] in self.FILTER_OPERATORS.keys():
            return u'.'.join(tokens[:-1]), tokens[-1]
        return u'.'.join(tokens), ""