Specifies the side of the reference part where to add the part.
OptionalratioSpecifies the proportional size of the part relative to the reference part.
The ratio is the closed interval [0,1]. If not set, defaults to 0.5.
OptionalrelativeSpecifies the part which to use as the reference part to lay out the part. If not set, the part will be aligned relative to the root of the layout.
Describes how to lay out a part relative to another part.