fix lint and better interface definition
fix lint and better interface definition

georgemarshall/DefinitelyTyped,dsebastien/DefinitelyTyped,borisyankov/DefinitelyTyped,markogresak/DefinitelyTyped,georgemarshall/DefinitelyTyped,magny/DefinitelyTyped,mcliment/DefinitelyTyped,magny/DefinitelyTyped,georgemarshall/DefinitelyTyped,dsebastien/DefinitelyTyped,borisyankov/DefinitelyTyped,georgemarshall/DefinitelyTyped