def __init__(self, allow_extra_system_messages: bool = False) -> None:
        """The `allow_extra_system_messages` instance variable allows the caller to specify that the prompt
        should be allowed to contain system messages after the very first one."""

        self._messages: list[ChatMessage] = []
        self._allow_extra_system_messages = allow_extra_system_messages
The `allow_extra_system_messages` instance variable allows the caller to specify that the prompt
        should be allowed to contain system messages after the very first one.
neuron_explainer/explanations/prompt_builder.py