fn __action510<'i, L>(
    ctx: &ParseContext,
    __0: (LexerPosition, Option<FunctionParameterDeclaration>, LexerPosition),
    __1: (LexerPosition, Vec<FunctionParameterDeclaration>, LexerPosition),
) -> Vec<FunctionParameterDeclaration> ⓘwhere
    L: HasLexerError,