"""Collect candidates from a specified round in a transcript, prioritizing answers and falling back to arguments.

This function iterates over each agent in the transcript and collects their latest record for the specified round. 
It prioritizes the 'answer' field, and if it is empty or missing, it falls back to the 'argument' field. 
Only non-empty text is included in the result.

Args:
    transcript (list): A list of dictionaries representing the transcript records. Each record should contain 
                       at least 'agent_id', 'round', and optionally 'answer' and 'argument' fields.
    num_agents (int): The total number of agents to consider in the transcript.
    round_index (int): The specific round index to collect candidates from.

Returns:
    list: A list of dictionaries, each containing 'agent_id' and 'text' keys. The 'text' is derived from the 
          'answer' or 'argument' field, whichever is non-empty and prioritized.
"""