code: public static boolean equalsIgnoreCase(String str1, String... strs) {
          if (strs != null) {
              for (String element : strs) {
                  if ((str1 != null && str1.equalsIgnoreCase(element)) || (str1 == null && element == null)) {
                      return true; // found
                  }
              }
              return false;
          } else {
              return str1 == null; // if both are null, it means equal
          }
      }
docs: ======