code: def is_monotonic_increasing(self):
          
  
          # reversed() because lexsort() wants the most significant key last.
          values = [self._get_level_values(i).values
                    for i in reversed(range(len(self.levels)))]
          try:
              sort_order = np.lexsort(values)
              return Index(sort_order).is_monotonic
          except TypeError:
  
              # we have mixed types and np.lexsort is not happy
              return Index(self.values).is_monotonic
docs: return if the index is monotonic increasing (only equal or
          increasing) values.