Factored out string key access
Factored out string key access

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