code: def test_access_content():
      chunk = StreamingChunk(
          content="Test content", meta={"key": "value"}
      )
      assert chunk.content == "Test content"
  
imports: import pytest
  from haystack.dataclasses import StreamingChunk
label_desc: Use image node_id 3 for calling a global function with example usage: test_access_content() without return types