code: public static boolean containsWhitespace(@Nullable final CharSequence str) {
      if (!StringUtils.hasLength(str)) {
        return false;
      }
  
      final int strLen = str.length();
      for (int i = 0; i < strLen; i++) {
        if (Character.isWhitespace(str.charAt(i))) {
          return true;
        }
      }
      return false;
    }
docs: Check whether the given {@code CharSequence} contains any whitespace characters.
  
  @param str the {@code CharSequence} to check (may be {@code null})
  @return {@code true} if the {@code CharSequence} is not empty and contains at least 1
  whitespace character
  @see Character#isWhitespace