This class represents a view of a set of project data that has been
instantiated within an MS Project file. View data is instantiated when a user
first looks at a view in MS Project. Each "screen" in MS Project, for example
the Gantt Chart, the Resource Sheet and so on are views. If a user has not
looked at a view (for example the Resource Usage view), information about
that view will not be present in the MPP file.