[Feature Request] add api to get differents properties(or fields) when map to exists dst?

[sgf]

Could be add some api to compare differents properties(or fields) with two instance of same class ?
i know we can use reflection,but performance slow.

like:

//same class  (ClassAObj1 vs ClassAObj2)
var fieldNames= ClassAObj1.Diff(ClassAObj2);  //Api-1 get different fieldnames,but not map
bool hasDifferents= ClassAObj1.MapDiff(ClassAObj2,out string[] fieldsName);  //Api-2 get get different fieldnames and map them
//not same class (ClassAObj1 vs ClassBObj2)
var fieldNames= ClassAObj1.Diff(ClassBObj2);  //Api-1 get different fieldnames,but not map
bool hasDifferents= ClassAObj1.MapDiff(ClassBObj2,out string[] fieldsName);  //Api-2 get get different fieldnames and map them

//same like mapper's config it will use the global config(custom ignore some properties(or fields) ),that's will be better.

why need:
if i got not differents,then i wont need to update to database.

[sgf]

mark a link agileobjects/AgileMapper#229