The CANCEL COVERAGE Collector command cancels the collection of
    test coverage data at the program locations specified by the node
    specification or by the /ALL qualifier. Any node specifications
    you cancel must have been established by previous SET COVERAGE
    commands. If you first establish test coverage measurement at
    a program location with SET COVERAGE and then cancel it with
    CANCEL COVERAGE, no data is gathered at that location when the GO
    command is entered.