void initAdd(int bitSize, int bitOffset) {
		if (!editUseEnabled) {
			throw new IllegalStateException("component not constructed for edit use");
		}
		editMode = EditMode.ADD;
		editOrdinal = -1;
		editComponent = null;
		refresh(bitSize, bitOffset);
	}
Update the size and offset of the allocation unit.  Since this can
affect the size of this component, its bounds will be updated the component
repainted.
@param byteSize allocation byte size
@param byteOffset offset of allocation from start of composite
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/compositeeditor/BitFieldPlacementComponent.java