mg = new GeneratorAdapter(ACC_PUBLIC + ACC_STATIC, m, null, null, cw);
mg.getStatic(Type.getType(System.class),
"out",
Type.getType(PrintStream.class));
mg.push("Hello world!");
mg.invokeVirtual(Type.getType(PrintStream.class),
Method.getMethod("void println (String)"));
mg.returnValue();
mg.endMethod();
cw.visitEnd();