sandbox/src/main/java/org/robolectric/internal/bytecode/ClassInstrumentor.java
protected void instrumentNativeMethod(MutableClass mutableClass, MethodNode method) {
    method.access = method.access & ~Opcodes.ACC_NATIVE;

    RobolectricGeneratorAdapter generator = new RobolectricGeneratorAdapter(method);
    Type returnType = generator.getReturnType();
    generator.pushDefaultReturnValueToStack(returnType);
    generator.returnValue();
  }
protected void instrumentNativeMethod(MutableClass mutableClass, MethodNode method) {
    method.access = method.access & ~Opcodes.ACC_NATIVE;

    RobolectricGeneratorAdapter generator = new RobolectricGeneratorAdapter(method);
    Type returnType = generator.getReturnType();
    generator.pushDefaultReturnValueToStack(returnType);
    generator.returnValue();
  }
Creates native stub which returns the default return value.

@param mutableClass Class to be instrumented
@param method Method to be instrumented, must be native