code: public static <T> T getInternalState(Object object, String fieldName, Class<?> where) {
  		return WhiteboxImpl.getInternalState(object, fieldName, where);
  	}
docs: Get the value of a field using reflection. Use this method when you need
  to specify in which class the field is declared. This might be useful
  when you have mocked the instance you are trying to access.
  
  @param object
  the object to modify
  @param fieldName
  the name of the field
  @param where
  which class the field is defined