docs: def min(self, spec):
          """Adds `min` operator that specifies lower bound for specific index.
  
          :Parameters:
            - `spec`: a list of field, limit pairs specifying the inclusive
              lower bound for all keys of a specific index in order.
  
          .. versionadded:: 2.7
          """
          if not isinstance(spec, (list, tuple)):
              raise TypeError("spec must be an instance of list or tuple")
  
          self.__check_okay_to_chain()
          self.__min = SON(spec)
          return self