code: @Override
  	public void delete(Object entity) {
  		if (entity == null) {
  			throw new IllegalArgumentException("'entity' must not be [" + entity + "]");
  		}
  		
  		if (operation != Log.Operation.GET) {
  			throw new IllegalStateException("Log [" + operation + "] -> ["
  					+ Log.Operation.DELETE
  					+ "] is not allowed: previous operation must be ["
  					+ Log.Operation.GET + "]");
  		}
  		
  		operation = Log.Operation.DELETE;
  	}
docs: Deletes the specified entity from the Google App Engine Datastore.
  
  @param entity An entity instance to be deleted.