def _maybe_append_user_content(self, llm_request: LlmRequest):
    """Appends a user content, so that model can continue to output.

    Args:
      llm_request: LlmRequest, the request to send to the Gemini model.
    """
    # If no content is provided, append a user content to hint model response
    # using system instruction.
    if not llm_request.contents:
      llm_request.contents.append(
          types.Content(
              role='user',
              parts=[
                  types.Part(
                      text=(
                          'Handle the requests as specified in the System'
                          ' Instruction.'
                      )
                  )
              ],
          )
      )
      return

    # Insert a user content to preserve user intent and to avoid empty
    # model response.
    if llm_request.contents[-1].role != 'user':
      llm_request.contents.append(
          types.Content(
              role='user',
              parts=[
                  types.Part(
                      text=(
                          'Continue processing previous requests as instructed.'
                          ' Exit or provide a summary if no more outputs are'
                          ' needed.'
                      )
                  )
              ],
          )
      )
Appends a user content, so that model can continue to output.

    Args:
      llm_request: LlmRequest, the request to send to the Gemini model.
    
src/google/adk/models/base_llm.py