protected void setVertexAttributes(AttributedVertex vertex, CodeBlock bb, boolean isEntry) {

		String vertexType = BODY;

		Address firstStartAddress = bb.getFirstStartAddress();
		if (firstStartAddress.isExternalAddress()) {
			vertexType = EXTERNAL;
		}
		else if (isEntry) {
			vertexType = ENTRY;
		}
		else {
			FlowType flowType = bb.getFlowType();
			if (flowType.isTerminal()) {
				vertexType = EXIT;
			}
			else if (flowType.isComputed()) {
				vertexType = SWITCH;
			}
			else if (flowType == RefType.INDIRECTION) {
				vertexType = DATA;
			}
			else if (flowType == RefType.INVALID) {
				vertexType = BAD;
			}
		}
		vertex.setVertexType(vertexType);
	}
Determine if the specified block is an entry node.
@param block the basic block to test
@return true  if the specified block is an entry node.
@throws CancelledException if the operation is cancelled
Ghidra/Features/ProgramGraph/src/main/java/ghidra/graph/program/BlockGraphTask.java