docs: public <T> String marshal(final T object) {
  
          if (object == null) {
              throw new IllegalArgumentException("object parameter is null");
          }
  
          ObjectWriter writer = objectMapper.writer().withDefaultPrettyPrinter();
          String results = null;
          try {
              results = writer.writeValueAsString(object);
          } catch (JsonGenerationException e) {
              System.err.println("JsonGenerationException, message=" + e.getMessage());
          } catch (JsonMappingException e) {
              e.printStackTrace();
              System.err.println("JsonMappingException, message=" + e.getMessage());
          } catch (IOException e) {
              System.err.println("IOException, message=" + e.getMessage());
          }
  
          return (results);
      }