内部方法的KOTLIN ANTLR语法解析错误

如何解决内部方法的KOTLIN ANTLR语法解析错误

获取以下Kotlin代码的解析错误。我正在使用Kotlin语法形式的ANTLR v4（https://github.com/antlr/grammars-v4/tree/master/kotlin/kotlin）

class BaseViewHelperTest {
@Test
@Throws(InterruptedException::class)
fun completetest() {
    mConnectToGameLabUseCase.execute(object : DefaultCompletableObserver() {
        override fun onComplete() {
            super.onComplete()
            unlock()
        }

        override fun onError(e: Throwable) {
            super.onError(e)
            failure() 
        }
    })
    lock()
  }
}

错误详细信息：

line 12:12 no viable alternative at input '(object:DefaultCompletableObserver(){overridefunonComplete(){super.onComplete()unlock()}'
line 9:21 no viable alternative at input 'overridefun'
line 9:38 mismatched input '{' expecting {',',RPAREN}
line 14:12 mismatched input 'override' expecting {<EOF>,NL,';'}

以上语法需要进行哪些更改以支持此操作？