code: def _merge_results(self, lhs: cudf.DataFrame, rhs: cudf.DataFrame):
      # semi-join result includes only lhs columns
      return lhs._data, lhs._index
  
file_path: cudf/python/cudf/cudf/core/join/join.py
imports: from __future__ import annotations
  import itertools
  import warnings
  from typing import Any, ClassVar, List, Optional
  import cudf
  from cudf import _lib
  from cudf._lib.types import size_type_dtype
  from cudf.core.copy_types import GatherMap
  from cudf.core.join._join_helpers import _coerce_to_tuple, _ColumnIndexer, _IndexIndexer, _match_join_keys
label_desc: Use image node_id 1 for calling the MergeSemi obj's underlying member method code with example usage: obj._merge_results(lhs, rhs) and returns: lhs,  lhs