question: public static String dump ( Map < ? , ? > map ) { StringBuilder stringBuilder = new StringBuilder ( ) ; for ( Map . Entry < ? , ? > entry : map . entrySet ( ) ) { stringBuilder . append ( entry . getKey ( ) ) ; stringBuilder . append ( " : " ) ; stringBuilder . append ( entry . getValue ( ) ) ; } return stringBuilder . toString ( ) ; }
target:  Dump map value into String.