"TypeError: Class constructor Lexer cannot be invoked without 'new'"

[queenlixiaoman]

$antlr4 -Dlanguage=JavaScript SplParser.g4

Generate file：SplParserLexer.js.

In SplParserLexer.js codes:

function SplParserLexer(input) {
antlr4.Lexer.call(this, input);
this._interp = new antlr4.atn.LexerATNSimulator(this, atn, decisionsToDFA, new antlr4.PredictionContextCache());
return this;
}

Browser error："TypeError: Class constructor Lexer cannot be invoked without 'new'"

How to solve it,please?