public static class Person {
        @Form(prefix="telephoneNumbers") List<TelephoneNumber> telephoneNumbers;
        @Form(prefix="address") Map<String, Address> addresses;
    }
...
    request.addFormHeader("telephoneNumbers[0].countryCode", "31");
    request.addFormHeader("telephoneNumbers[0].number", "0612345678");
    request.addFormHeader("telephoneNumbers[1].countryCode", "91");
    request.addFormHeader("telephoneNumbers[1].number", "9717738723");
    request.addFormHeader("address[INVOICE].street", "Main Street");
    request.addFormHeader("address[INVOICE].houseNumber", "2");
    request.addFormHeader("address[SHIPPING].street", "Square One");
    request.addFormHeader("address[SHIPPING].houseNumber", "13");