def METHOD_NAME(self, fmt: str) -> ProtoSerializer:
    """Get a serializer for a format.
    Args:
        fmt: The format to get a serializer for.
    Returns:
        ProtoSerializer: The serializer for the format.
    Raises:
        ValueError: If the format is not supported.
    """
    try:
        return self._serializers[fmt]
    except KeyError:
        raise ValueError(
            f"Unsupported format: '{fmt}'. Supported formats are: {self._serializers.keys()}"
        ) from None