code: def test_merge_one():
      component = MergeLoop(expected_type=int, inputs=["in_1"])
      results = component.run(in_1=1)
      assert results == {"value": 1}
  
file_path: haystack/test/core/sample_components/test_merge_loop.py
imports: from typing import Dict
  import pytest
  from haystack.core.errors import DeserializationError
  from haystack.testing.sample_components import MergeLoop
label_desc: Use image node_id 12 for calling a global function with example usage: test_merge_one() without return types