I represent a selector and its argument values.

Generally, the system does not use instances of Message for efficiency reasons. However, when a message is not understood by its receiver, the interpreter will make up an instance of me in order to capture the information involved in an actual message transmission. This instance is sent it as an argument with the message doesNotUnderstand: to the receiver.

	printing
	printOn: storeOn:

	private
	setSelector:arguments:

	sending
	sentTo:

	accessing	top
	argument Answer the first (presumably sole) argument
	argument: Change the first argument to newValue and answer self
	arguments Answer the arguments of the receiver.
	selector Answer the selector of the receiver.
	sends: answer whether this message's selector is aSelector

	printing	top
	printOn: Refer to the comment in Object|printOn:.
	storeOn: Refer to the comment in Object|storeOn:.

	private	top
	setSelector:arguments:

	sending	top
	sentTo: answer the result of sending this message to receiver

	instance creation	top
	selector: Answer an instance of me with unary selector, aSymbol.
	selector:argument: Answer an instance of me whose selector is aSymbol and single argument is anObject.
	selector:arguments: Answer an instance of me with selector, aSymbol, and arguments, anArray.