code: def y_offset(self):
          
          try:
              if self._part:
                  value = self._part.y_offset
              else:
                  value = self._buffer.offset_y
          except InvalidParameterException:
              value = self._node_map.OffsetY.value
          return value
docs: :return: The Y offset of the data in the buffer in number of pixels from the image origin to handle areas of interest.