question: public static String implode ( Collection < String > items , String delimiter ) { Parameters . notNull ( "items" , items ) ; Parameters . notNull ( "delimiter" , delimiter ) ; if ( items . isEmpty ( ) ) { return "" ; } StringBuilder buffer = new StringBuilder ( 200 ) ; boolean first = true ; for ( String s : items ) { if ( ! first ) { buffer . append ( delimiter ) ; } buffer . append ( s ) ; first = false ; } return buffer . toString ( ) ; }
target:  Implode collection of strings to one string using delimiter.