Can't write miniKotlin function without arguments

[AlexKozm]

Function definition allows to create functions without parameters:

functionDeclaration
    : FUN IDENTIFIER LPAREN parameterList? RPAREN COLON type block
    ;

Function call does allow to call functions without arguments:

expression
    : IDENTIFIER LPAREN argumentList RPAREN            # FunctionCallExpr

Probably question mark is missing after argumentList:

expression
    : IDENTIFIER LPAREN argumentList? RPAREN           # FunctionCallExpr