code: public static final boolean stringIsBlank(final String string) {
  
          if (string == null || string.length() == 0) {
              return true;
          }
  
          int stringLength = string.length();
          for (int i = 0; i < stringLength; i++) {
              if (Character.isWhitespace(string.charAt(i)) == false) {
                  return false;
              }
          }
          return true;
      }
docs: Checks if the provided String is blank, meaning it is empty or contains whitespace only.
  
  @param string
  the String to check, may be {@code null}
  @return {@code true} if the String is blank, false otherwise