These are the sub-properties that determine what an expanded 'Flow Collapse Button' looks like, if it uses an icon, and if it has bubble help.
Optional. Specify the text to show on the button when the Panels before this Panel are colllapsed(i.e. docked or hidden). If you don't specify a value a default the >> symbol will be used.
The Icon to show for expanding a Panel.
The Icon to show when the 'flow collapse' button is pressed to expand it.
Bubble help text to add to the button so that users can see what the button does if they hover over it.