code: def expect_multicolumn_values_to_be_unique(self,
                                                column_list,
                                                ignore_row_if="all_values_are_missing",
                                                result_format=None, include_config=False, catch_exceptions=None, meta=None
                                                ):
          
          raise NotImplementedError
docs: Expect the values for each row to be unique across the columns listed.
  
          Args:
              column_list (tuple or list): The first column name
  
          Keyword Args:
              ignore_row_if (str): "all_values_are_missing", "any_value_is_missing", "never"
  
          Other Parameters:
              result_format (str or None): \
                  Which output mode to use: `BOOLEAN_ONLY`, `BASIC`, `COMPLETE`, or `SUMMARY`.
                  For more detail, see :ref:`result_format <result_format>`.
              include_config (boolean): \
                  If True, then include the expectation config as part of the result object. \
                  For more detail, see :ref:`include_config`.
              catch_exceptions (boolean or None): \
                  If True, then catch exceptions and include them as part of the result object. \
                  For more detail, see :ref:`catch_exceptions`.
              meta (dict or None): \
                  A JSON-serializable dictionary (nesting allowed) that will be included in the output without modification. \
                  For more detail, see :ref:`meta`.
  
          Returns:
              A JSON-serializable expectation result object.
  
              Exact fields vary depending on the values passed to :ref:`result_format <result_format>` and
              :ref:`include_config`, :ref:`catch_exceptions`, and :ref:`meta`.