project
+ src
++ javaextension
+++ Helper.java
++ template
+++ Template.xpt
+++ GeneratorExtension.ext
+++ OtherExtension.ext

«IMPORT ...»

«EXTENSION template::GeneratorExtensions»

«DEFINE ... FOR ...»
	«FILE "test.txt"»
		«helloWorld()»
	«ENDFILE»
«ENDDEFINE»

import ...;
...
String helloWorld() : JAVA javaextension.Helper.getHelloWorld();

import ...;
...
String getWorld() : "World";

public class Helper implements IExecutionContextAware {
	private String hello;

	public Helper() {
		hello = "Hello";
	}

	public String getHelloWorld() {
		ExtensionFile file;
		String result = "unknown";
		try {
			file = ParseFacade.file(new FileReader(new File(
					"src/template/OtherExtension.ext")), "OtherExtension");
			ExecutionContextImpl ec = (ExecutionContextImpl) getExecutionContext()
					.cloneWithResource(file);
			ExpressionFacade ef = new ExpressionFacade(ec);
			result = (String) ef.evaluate("getWorld()");
			// setExecutionContext(ec);
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		}
		return hello + " " + result;
	}

	private ExecutionContext ctx;

	public ExecutionContext getExecutionContext() {
		return ctx;
	}

	public void setExecutionContext(ExecutionContext ctx) {
		this.ctx = ctx;
	}
}

Hello World

    XpandExecutionContext xpandContext = get XpandExecutionContext();
    XpandFacade facade = XpandFacade.create(xpandContext);
    facade.evaluate("templates::TemplateFile::defineMethod", modelElement);