code: def shift(
              self,
              periods: int = 1,
              fill_value: object = None,
      ) -> ABCExtensionArray:
          
          # Note: this implementation assumes that `self.dtype.na_value` can be
          # stored in an instance of your ExtensionArray with `self.dtype`.
          if not len(self) or periods == 0:
              return self.copy()
  
          if isna(fill_value):
              fill_value = self.dtype.na_value
  
          empty = self._from_sequence(
              [fill_value] * min(abs(periods), len(self)),
              dtype=self.dtype
          )
          if periods > 0:
              a = empty
              b = self[:-periods]
          else:
              a = self[abs(periods):]
              b = empty
          return self._concat_same_type([a, b])
docs: Shift values by desired number.
  
          Newly introduced missing values are filled with
          ``self.dtype.na_value``.
  
          .. versionadded:: 0.24.0
  
          Parameters
          ----------
          periods : int, default 1
              The number of periods to shift. Negative values are allowed
              for shifting backwards.
  
          fill_value : object, optional
              The scalar value to use for newly introduced missing values.
              The default is ``self.dtype.na_value``
  
              .. versionadded:: 0.24.0
  
          Returns
          -------
          shifted : ExtensionArray
  
          Notes
          -----
          If ``self`` is empty or ``periods`` is 0, a copy of ``self`` is
          returned.
  
          If ``periods > len(self)``, then an array of size
          len(self) is returned, with all values filled with
          ``self.dtype.na_value``.