public <D, V> void iget(FieldId<D, ? extends V> fieldId, Local<V> target, Local<D> instance) {
    addInstruction(
        new ThrowingCstInsn(
            Rops.opGetField(target.type.ropType),
            sourcePosition,
            RegisterSpecList.make(instance.spec()),
            catches,
            fieldId.constant));
    moveResult(target, true);
  }
Copies the value in instance field {@code fieldId} of {@code instance} to {@code target}.
android/android_framework/dex-maker/src/main/java/com/android/dx/Code.java