private ExtensionManager getExtensionManager() {
		if (extensionManager == null) {
			extensionManager = new ExtensionManager(this);
		}
		return extensionManager;
	}
We need to do this here, since our parent constructor calls methods on us that need the 
extension manager.
@return the extension manager
Ghidra/Framework/Project/src/main/java/ghidra/framework/project/tool/GhidraTool.java