@Override
	public int hashCode() {
		return System.identityHashCode(domainFile);
	}
Get the domain file if this node represents a file object versus a folder; interface method
for DomainDataTransfer.

@return null if this node represents a domain folder
Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/DomainFileNode.java