code: def inner_join_impl(other, sequence):
      
      seq_dict = {}
      for element in sequence:
          seq_dict[element[0]] = element[1]
      seq_kv = seq_dict
      other_kv = dict(other)
      keys = seq_kv.keys() if len(seq_kv) < len(other_kv) else other_kv.keys()
      result = {}
      for k in keys:
          if k in seq_kv and k in other_kv:
              result[k] = (seq_kv[k], other_kv[k])
      return six.viewitems(result)
docs: Implementation for part of join_impl
      :param other: other sequence to join with
      :param sequence: first sequence to join with
      :return: joined sequence