duration property
Provide duration for the overall sliding time.
Here, 'overall sliding time' means, sliding from PanelState.dismissed to PanelState.expanded.
This will be adjusted when PanelController.dismiss, PanelController.close, PanelController.collapse, PanelController.expand or PanelController.setAnimatedPanelPosition are used. This will be calculated accordingly.
Default : 1000 milliseconds
Implementation
final Duration duration;