docstr: Test if the component runs correctly in the simplest happy path.
code: def test_run(self, test_files_path):
      """
      Test if the component runs correctly in the simplest happy path.
      """
      file_paths = [
          test_files_path / "txt" / "doc_1.txt",
          test_files_path / "txt" / "doc_2.txt",
          test_files_path
          / "audio"
          / "the context for this answer is here.wav",
          test_files_path / "images" / "apple.jpg",
      ]
  
      router = FileTypeRouter(
          mime_types=["text/plain", "audio/x-wav", "image/jpeg"]
      )
      output = router.run(sources=file_paths)
      assert output
      assert len(output["text/plain"]) == 2
      assert len(output["audio/x-wav"]) == 1
      assert len(output["image/jpeg"]) == 1
      assert not output["unclassified"]
  
file_path: haystack/test/components/routers/test_file_router.py
imports: import sys
  import pytest
  from haystack.components.routers.file_type_router import FileTypeRouter
  from haystack.dataclasses import ByteStream
label_desc: Use image node_id 1 for calling the TestFileTypeRouter obj's underlying member method code with example usage: obj.test_run(test_files_path) without return types