code: private Object getLengthOfObject(Object object, String functionName) throws TransformationOperationException {
          try {
              Method method = object.getClass().getMethod(functionName);
              return method.invoke(object);
          } catch (NoSuchMethodException e) {
              StringBuilder builder = new StringBuilder();
              builder.append("The type of the given field for the length step doesn't support ");
              builder.append(functionName).append(" method. So 0 will be used as standard value.");
              throw new TransformationOperationException(builder.toString(), e);
          } catch (IllegalArgumentException e) {
              throw new TransformationOperationException("Can't get length of the source field", e);
          } catch (IllegalAccessException e) {
              throw new TransformationOperationException("Can't get length of the source field", e);
          } catch (InvocationTargetException e) {
              throw new TransformationOperationException("Can't get length of the source field", e);
          }
      }
docs: Returns the length of the given object got through the method of the given function name