How can i set create_patch=true, and meanwhile get change_type in Diff #1897

I find that when i use commit1.diff(commit2,create_patch = true), chang_type of Diff is aways none. if create_patch = False, i kown that i can get chang_type of Diff , but I can get hunk text.

Can i get Diff text ,and meanWhile get chang_type of Diff?