@Override
		public int compare(GTreeNode o1, GTreeNode o2) {
			CallNode node1 = (CallNode) o1;
			CallNode node2 = (CallNode) o2;
			int addrCompare = node1.getSourceAddress().compareTo(node2.getSourceAddress());
			if (addrCompare != 0) {
				return addrCompare;
			}
			return Boolean.compare(node1.isCallReference, node2.isCallReference);

		}
Returns true if the reference associated with this node is a call reference type.
@return true if the reference associated with this node is a call reference type.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/calltree/CallNode.java