<oPushButton>:display() --> self

        display() is a method of the PushButton class that is used for
        showing a push button on the screen.  display() uses the values of
        the following instance variables to correctly show the push button in
        its current context, in addition to providing maximum flexibility in
        the manner a push button appears on the screen:  buffer, caption,
        col, colorSpec, hasFocus, row, and style.