code: def join(self, other):
          r
          assert self._load == other._load, 'loads must be the same'
          self._lists.extend(other._lists)
          self._cumlen.extend([c + self._len for c in other._cumlen])
          self._len += other._len
docs: r"""
          Args:
              other (?):
  
          CommandLine:
              python -m sortedcontainers.sortedlist join2
  
          Example:
              >>> from utool.experimental.dynamic_connectivity import *  # NOQA
              >>> self = EulerTourList([1, 2, 3, 2, 4, 2, 1], load=3)
              >>> other = EulerTourList([0, 5, 9, 5, 0], load=3)
              >>> result = self.join(other)
              >>> print(result)