@interface RLMPropertyChange : NSObject

/**
 The name of the property which changed.
 */
@property (nonatomic, readonly, strong) NSString *name;

/**
 The value of the property before the change occurred. This will always be `nil`
 if the change happened on the same thread as the notification and for `RLMArray`
 properties.

 For object properties this will give the object which was previously linked to,
 but that object will have its new values and not the values it had before the
 changes. This means that `previousValue` may be a deleted object, and you will
 need to check `invalidated` before accessing any of its properties.
 */
@property (nonatomic, readonly, strong, nullable) id previousValue;

/**
 The value of the property after the change occurred. This will always be `nil`
 for `RLMArray` properties.
 */
@property (nonatomic, readonly, strong, nullable) id value;
@end

public interface ObjectChangeset {
  boolean isDeleted();
  String[] getChangedField();
  isFieldChanged(String fieldName);
 
  public static class FieldChange<T> {
    T oldValue;
    T newValue;
  }

  // This will always return null for RealmList field.
  <E> FieldChange<E> getChange(E type, String fieldName);
}

public interface ObjectChangeset {
  boolean isDeleted();
  String[] getChangedField();
  isFieldChanged(String fieldName);
 
  Long getOldLongValue(String fieldName);
  Long getNewLongValue(String fieldName);
  Date getOldDateValue(String fieldName);
  Date getNewDateValue(String fieldName);
  // ... Other getters
}