Sets the preferred sidebar width as a fraction of the total width of self.
The preferred width is additionally limited by propertyOverlaySplitView:min-sidebar-width and propertyOverlaySplitView:max-sidebar-width.
The sidebar widget can be allocated with larger width if its own minimum width exceeds the preferred width.
the preferred width fraction
Sets the preferred sidebar width as a fraction of the total width of self.
The preferred width is additionally limited by propertyOverlaySplitView:min-sidebar-width and propertyOverlaySplitView:max-sidebar-width.
The sidebar widget can be allocated with larger width if its own minimum width exceeds the preferred width.