A display for displaying a ProbeMap across a number of objects..
This ProbeDisplay extracts all the variable probes from a probe map and creates a variable probe entry for each object in the list provided by the user.
The create: message creates a new instance of a type with default options. The zone argument specifies the source of storage for the new object. The receiving object of this message is a previously defined type object. The message is declared as a class message (with a + declaration tag) to indicate that the message is accepted only by the type object itself rather than an already created instance of the type (which a - declaration tag otherwise defines). The create: message returns the new object just created. This object is an instance of some class selected to implement the type. The class which a type selects to implement an object may be obtained by the getClass message, but is not otherwise visible to the calling program. A caller never refers to any class name when creating objects using these messages, only to type names, which are automatically published as global constants from any @protocol declaration.