makes sure #children is writable . concode_field_sep TreeString node concode_elem_sep Map<String,Child> children concode_elem_sep Child root concode_elem_sep Map<String,Child> NO_CHILDREN concode_field_sep Child intern concode_elem_sep TreeString intern concode_elem_sep TreeString intern concode_elem_sep Child split concode_elem_sep int commonPrefix concode_elem_sep void dedup concode_elem_sep void dedup
void function ( ) { if ( children == NO_CHILDREN ) { children = new HashMap < String , Child > ( ) ; } }