// Get the VirtualMachine implementation.  
        VirtualMachine vm = VirtualMachine.getVirtualMachine();
        
        // Instantiate a new CompilationUnit.  The argument to the
        // compilation unit is the "codebase" or directory where the
        // compilation unit should be written.
        //
        // Make a new compilation unit rooted to the given sourcepath.
        CompilationUnit unit = vm.newCompilationUnit("/tmp");
        
        // Set the package namespace.
        unit.setNamespace("net.sourceforge.jenesis4java.example");
        
        // Add an import statement for fun.
        unit.addImport("java.io.Serializable");
        
        // Comment the package with a javadoc (DocumentationComment).
        unit.setComment(Comment.D, "Auto-Generated using the Jenesis Syntax API");
        
        // Make a new class.
        PackageClass cls = unit.newClass("HelloWorld");
        // Make it a public class.
        cls.setAccess(Access.PUBLIC);
        // Extend Object just for fun.
        cls.setExtends("Object");
        // Implement serializable just for fun.
        cls.addImplements("Serializable");
        // Comment the class with a javadoc (DocumentationComment).
        unit.setComment(Comment.D, "The HelloWorld example class.");
        
        // Make a new Method in the Class having type VOID and name "main".
        ClassMethod method = cls.newMethod(vm.newType(Type.VOID), "main");
        // Make it a public method.
        method.setAccess(Access.PUBLIC);
        // Make it a static method
        method.isStatic(true);
        // Add the "String[] argv" formal parameter.
        method.addParameter(vm.newArray("String", 1), "argv");

        // Create a new Method Invocation expression.
        Invoke println = vm.newInvoke("System.out", "println");
        // Add the Hello World string literal as the sole argument.
        println.addArg(vm.newString("Hello World!"));
        // Add this expression to the method in a statement.
        method.newStmt(println);

        // Write the java file.
        unit.encode();