code: private static String checkConstantValue(@CompileTimeConstant final String value) {
      for (int i = 0; i < value.length(); i++) {
        char c = value.charAt(i);
        if (c == '<' || c == '>' || c == '"' || c == '\'' || c == ';') {
          throw new IllegalArgumentException(
              "Value contains HTML/CSS meta-characters ([<>\"';]): " + value);
        } else if (
              value.startsWith("/*", i) || value.startsWith("*/", i) || value.startsWith("//", i)) {
            throw new IllegalArgumentException(
                "Value contains CSS comment marker (/*, */ or //): " + value);
        }
      }
      return value;
    }
docs: Throws IllegalArgumentException if {@code value} contains any of a few blacklisted characters
  which would change the syntactic structure of the CSS or entirely break out of the HTML style
  attribute.