code: public String getString(String key) {
  
      Object obj = get(key);
  
      try {
        return (String) obj;
      } catch (Exception e) {
        throw new ClassCastException("Identified object is not a String.");
      }
    }
docs: Retrieve the identified <code>String</code> value from the <code>JobDataMap</code>.
  
  @throws ClassCastException if the identified object is not a String.