Class hierarchy:
~~~~~~~~~~~~~~~~~     Color

                      Stack

                      Loc ----> Cursor
                            |-> Frame(Color)         +-> Choice(Cursor)
                            +-> Box(Color) ---> Win ---> Mnu(Cursor)
                                            +-> Window(Frame) ---> UpWindow
                                                               +-> Task(Mnu)
                      +----------------(Task)----------------------+
                      |
                      |--> Info --> FInfo
                      +--> Browse ---> ABrowse ---> UpABrowse
                                   +-> DBrowse ---> UpDBrowse
                                                |-> View(Dbf) --> Mask
                      Dbf(UpWindow)             +-> Report(FInfo)

                      Menu(View,Dbf,Stack,UpABrowse)
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Example: class Box has a parent class Loc and uses the class Color.