Bottom
Top edge treatment for the bottom app bar which "cradles" a circular .
This edge features a downward semi-circular cutout from the edge line. The two corners created by the cutout can optionally be rounded. The circular cutout can also support a vertically offset FloatingActionButton; i.e., the cut-out need not be a perfect semi-circle, but could be an arc of less than 180 degrees that does not start or finish with a vertical path. This vertical offset must be positive.