code: public static boolean isContentAlwaysEmptyWithValidation(
              HttpStatus status, HttpData content, HttpHeaders trailingHeaders) {
          if (!isContentAlwaysEmpty(status)) {
              return false;
          }
  
          if (!content.isEmpty()) {
              throw new IllegalArgumentException(
                      "A " + status + " response must have empty content: " + content.length() + " byte(s)");
          }
          if (!trailingHeaders.isEmpty()) {
              throw new IllegalArgumentException(
                      "A " + status + " response must not have trailing headers: " + trailingHeaders);
          }
  
          return true;
      }
docs: Returns {@code true} if the content of the response with the given {@link HttpStatus} is expected to
  be always empty (1xx, 204, 205 and 304 responses.)
  
  @throws IllegalArgumentException if the specified {@code content} or {@code trailingHeaders} are
  non-empty when the content is always empty