code: def _proc_builtin(self, tarfile):
          
          self.offset_data = tarfile.fileobj.tell()
          offset = self.offset_data
          if self.isreg() or self.type not in SUPPORTED_TYPES:
              # Skip the following data blocks.
              offset += self._block(self.size)
          tarfile.offset = offset
  
          # Patch the TarInfo object with saved global
          # header information.
          self._apply_pax_info(tarfile.pax_headers, tarfile.encoding, tarfile.errors)
  
          return self
docs: Process a builtin type or an unknown type which
             will be treated as a regular file.