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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 filter(self, field_name, operand, value):
 """Adds a filter to report Notes: All filters are currently AND'ed together Args: field_name (str):
 Target field name to filter on operand (str):
 Operand used in comparison. See `swimlane.core.search` for options value: Target value used in comparision """

        if operand not in self._FILTER_OPERANDS:
            raise ValueError('Operand must be one of {}'.format(', '.join(self._FILTER_OPERANDS)))

        # Use temp Record instance for target app to translate values into expected API format
        record_stub = record_factory(self._app)
        field = record_stub.get_field(field_name)

        self._raw['filters'].append({
            "fieldId": field.id,
            "filterType": operand,
            "value": field.get_report(value)
        })