public ResourceQuery<T> filter(String field, String op, String value) {
        String name = String.format("%s[%s]", field, op);
        uri_builder.addParameter(name, value);
        return this;
    }
public ResourceQuery < T > filter ( String field , String op , String value ) { String name = String . format ( "%s[%s]" , field , op ) ; uri_builder . addParameter ( name , value ) ; return this ; }
filtering