create a comparator which compares features by the attribute at the given index . the attribute at the index must be comparable . this will probably not work for heterogenous collections , unless the classes at the given index are the same . concode_field_sep java.util.Comparator BY_ID concode_elem_sep String name concode_elem_sep int idx concode_field_sep java.util.Comparator byAttributeName concode_elem_sep int compare concode_elem_sep int compare concode_elem_sep int compare concode_elem_sep int compareAtts concode_elem_sep int compareAtts
java . util . Comparator function ( final int arg0 ) { return new Index ( arg0 ) ; }