skip instanceof checks, fixes #571
skip instanceof checks, fixes #571

andykog/mobservable,mobxjs/mobx,mobxjs/mobx,mweststrate/MOBservable,mweststrate/MOBservable,mobxjs/mobx,mobxjs/mobx,andykog/mobx,mweststrate/MOBservable,andykog/mobservable,andykog/mobx