defalut is Open，but i what I need is closed...

[DavidMGT]

 for (PayDetail payDetail : loanDetails.getRepaymentList()) {
        Section<PayDetail, PayDetail> section = new Section<>();
        section.parent = payDetail;
        section.children.add(payDetail);
        section.expanded = false;
        binding.elLoanList.addSection(section);
        binding.elLoanList.addChild(payDetail, payDetail);

    }.

still is open.

[acousticksan]

for (PayDetail payDetail : loanDetails.getRepaymentList()) {
        Section<PayDetail, PayDetail> section = new Section<>();
        section.parent = payDetail;
        section.children.add(payDetail);
        section.expanded = false;
        binding.elLoanList.addSection(section);
    }