code: def _update_vdr_vxrheadtail(self, f, vdr_offset, VXRoffset):
          '''
          This sets a VXR to be the first and last VXR in the VDR
          '''
          # VDR's VXRhead
          self._update_offset_value(f, vdr_offset+28, 8, VXRoffset)
          # VDR's VXRtail
          self._update_offset_value(f, vdr_offset+36, 8, VXRoffsetf _update_vdr_vxrheadtail(self, f, vdr_offset, VXRoffset):
          '''
          This sets a VXR to be the first and last VXR in the VDR
          '''
          # VDR's VXRhead
          self._update_offset_value(f, vdr_offset+28, 8, VXRoffset)
          # VDR's VXRtail
          self._update_offset_value(f, vdr_offset+36, 8, VXRoffset)
docs: This sets a VXR to be the first and last VXR in the VDR