I am unable to compile

[iamDmon]

calendarView.shouldAnimateOnEnter(true)
                .setFirstDayOfWeek(Calendar.MONDAY)
                .setOnDateClickListener(this::onDateClick)
                .setOnMonthChangeListener(this::onMonthChange)
                .setOnDateLongClickListener(this::onDateLongClick)
                .setOnMonthTitleClickListener(this::onMonthTitleClick);

I get the error : Cannot resolve method onDateClick and all the other methods,
I know that I have to replace this with the object, but that doesnt work too. I tried replacing the lambda operator, but that fails too.

Can somebody please help me