parameters: (self, delta, save=True)
docstring: Apply a delta map to the fields.
  		Also saves the object.
docstring_summary: Apply a delta map to the fields.
  		Also saves the object.
docstring_tokens: Apply a delta map to the fields . Also saves the object .
function: def apply_delta(self, delta, save=True):
  		"""
  		Apply a delta map to the fields.
  		Also saves the object.
  		
  		"""
  		d = self.get_data()
  		fields = d.setdefault("fields", {})
  		
  		fields.update(delta)
  		
  		# Check for null-value keys and delete them
  		for key in delta.iterkeys():
  			if delta[key] == None:
  				del fields[key]
  		
  		self.set_data(d)
  		
  		if save:
  			self.save()
function_tokens: def apply_delta ( self , delta , save = True ) : d = self . get_data ( ) fields = d . setdefault ( "fields" , { } ) fields . update ( delta ) # Check for null-value keys and delete them for key in delta . iterkeys ( ) : if delta [ key ] == None : del fields [ key ] self . set_data ( d ) if save : self . save ( )