Represents the serialized json describing a change that originates from somewhere other than the user. For example a range validation is a GridSerializer.SerializedProp.
protected class SerializedProp
GridSerializer.SerializedChanges are changes made by the user. GridSerializer.SerializedUpdate sends the changes, both GridSerializer.SerializedProp and GridSerializer.SerializedChanges, back to the server.
See also GridSerializer.SerializedChange<T>and GridSerializer.SerializedUpdate<T>.