docs: public static String toJsonObject(String[] arr)
      {
          if ( arr == null ) {
              return null;
          }
          
          StringBuffer sb = new StringBuffer();
          sb.append('{');
          for ( String ele : arr ) {
              if ( sb.length() == 1 ) {
                  sb.append('"').append(ele).append("\":true");
              } else {
                  sb.append(",\"").append(ele).append("\":true");
              }
          }
          sb.append('}');
          
          return sb.toString();
      }