Fix handling of text_message_outputs output structure in parallel translation example

[mshsheikh]

Problem:
The code assumed ItemHelpers.text_message_outputs() returned a single string per result (e.g., "Hola mundo"), but it actually returns a list of strings (e.g., ["Hola", "Mundo"]). This caused a TypeError when joining outputs.

Example of Failure:

outputs = [
    ["Hola", "Mundo"],  # From text_message_outputs
    ["Buenos días"],
    ["Cómo estás"],
]
translations = "\n\n".join(outputs)  # ❌ TypeError: can't join list to str

Changes:

• Wrap text_message_outputs(...) with " ".join(...) to safely flatten each agent’s output into a single string:

  outputs = [
      " ".join(ItemHelpers.text_message_outputs(res_1.new_items)),
      " ".join(ItemHelpers.text_message_outputs(res_2.new_items)),
      " ".join(ItemHelpers.text_message_outputs(res_3.new_items)),
  ]

Benefits:

• Prevents TypeError by ensuring all outputs are strings.
• Maintains consistent formatting for the final joined output.
• Makes the example robust and easier to understand for users.

This change ensures the parallel translation workflow works reliably, even when agent outputs vary in structure.

[seratch]

Thanks for reporting this. I don't think this is the fundamental solution as the helper method is supposed to return a single string: https://github.com/openai/openai-agents-python/blob/v0.1.0/src/agents/items.py#L277-L284 could you help us identify the cause of the unexpected behavior?