@CheckReturnValue @Deprecated @Nonnull public static String join(@Nonnull String[] s,@Nonnull String delimiter){
  StringBuilder buffer=new StringBuilder();
  for (int i=0; i < s.length; i++) {
    buffer.append(s[i]);
    if (i < s.length - 1) {
      buffer.append(delimiter);
    }
  }
  return buffer.toString();
}

@ CheckReturnValue @ Deprecated @ Nonnull public static String join ( @ Nonnull String [ ] s , @ Nonnull String delimiter ) { StringBuilder buffer = new StringBuilder ( ) ; for ( int i = 0 ; i < s . length ; i ++ ) { buffer . append ( s [ i ] ) ; if ( i < s . length - 1 ) { buffer . append ( delimiter ) ; } } return buffer . toString ( ) ; }
join an array of strings , separated by a delimiter
