code: def append(self, other):
          
  
          to_concat = [self]
  
          if isinstance(other, (list, tuple)):
              to_concat = to_concat + list(other)
          else:
              to_concat.append(other)
  
          for obj in to_concat:
              if not isinstance(obj, Index):
                  raise TypeError('all inputs must be Index')
  
          names = {obj.name for obj in to_concat}
          name = None if len(names) > 1 else self.name
  
          return self._concat(to_concat, name)
docs: Append a collection of Index options together.
  
          Parameters
          ----------
          other : Index or list/tuple of indices
  
          Returns
          -------
          appended : Index