def METHOD_NAME(root: Tree) -> Optional[str]:
    in_expression_tree: Optional[Tree] = get_first_rule(root, "in_expression")
    if in_expression_tree is None:
        return None
    # Get list of terminal value
    # Remove any whitespaces
    # Remove any spaces
    return "".join(
        strip_char_from_list(
            remove_whitespaces_from_list(token_values(in_expression_tree)), " "
        )
    )