code: public static boolean valueIsScript(String propertyName) {
        return (getInstance().properties.containsKey(propertyName) && getInstance().properties.get(propertyName)
                                                                                              .startsWith(
                                                                                                 SCRIPT_PROPERTY));
     }
docs: Determines if the value of the given property is a script or not
  
  @param propertyName The name of the property to check
  @return True if the property exists and its value is a script