BottomAppBar.FabAlignmentMode The fabAlignmentMode determines the horizontal positioning of the cradle and the FAB which can be centered or aligned to the end. 
BottomAppBar.FabAnimationMode The fabAnimationMode determines the animation used to move the FAB between different alignment modes. 


BottomAppBar The Bottom App Bar is an extension of Toolbar that supports a shaped background that "cradles" an attached FloatingActionButton
BottomAppBar.Behavior Behavior designed for use with BottomAppBar instances. 
BottomAppBarTopEdgeTreatment Top edge treatment for the bottom app bar which "cradles" a circular FloatingActionButton