langchain/llms/human.py/_collect_user_input
def _collect_user_input(
    separator: Optional[str] = None, stop: Optional[List[str]] = None
) -> str:
    """Collects and returns user input as a single string."""
    separator = separator or "\n"
    lines = []

    while True:
        line = input()
        if not line:
            break
        lines.append(line)

        if stop and any(seq in line for seq in stop):
            break
    # Combine all lines into a single string
    multi_line_input = separator.join(lines)
    return multi_line_input