private void validateIncomingExpandedState(boolean expanding) {

		if (expanding) {
			if (!canExpandIncomingReferences()) {
				throw new IllegalStateException("Vertex cannot be expanded: " + this);
			}
			return;
		}

		// collapsing
		if (!isIncomingExpanded()) {
			throw new IllegalStateException("Vertex cannot be collapsed: " + this);
		}
	}
Sets to true if this vertex is showing all edges in the incoming direction
@param setExpanded true if this vertex is showing all edges in the incoming direction
Ghidra/Features/GraphFunctionCalls/src/main/java/functioncalls/graph/FcgVertexShapeProvider.java