code: public X getPrimaryID(T entity) {
  		if(mappingContext == null || conversionService == null) {
  			fetchMappingContextAndConversionService();
  		}
  
  		MongoPersistentEntity<?> persistentEntity = mappingContext.getPersistentEntity(entity.getClass());
  		MongoPersistentProperty idProperty = persistentEntity.getIdProperty();
  		if(idProperty == null) {
  			return null;
  		}
  		
  //		X idValue = BeanWrapper.create(entity, conversionService).getProperty(idProperty, this.primaryIDClass);
  		X idValue = (X) this.mappingContext.getPersistentEntity(this.entityClass).getPropertyAccessor(entity).getProperty(idProperty);
  		return idValue;
  	}
docs: Extract the value of the primary ID of the entity object
  
  @param entity
  the entity to get primary key value of
  
  @return the primary key value