code: public static void isEmpty(String text, String message) {
          if (StringUtils.isEmpty(text)) {
              throw new IllegalArgumentException(message);
          }
      }
docs: Assert that the given String has valid text content; that is, it must not
  be {@code null} and must contain at least one non-whitespace character.
  <pre class="code">Assert.hasText(name, "'name' must not be empty");</pre>
  
  @param text the String to check
  @param message the exception message to use if the assertion fails
  @see org.apache.commons.lang3.StringUtils#isEmpty