Preprocess option to Knockout binding's syntax

From the oficial documentation: http://knockoutjs.com/documentation/binding-preprocessing.html

knockout/knockout.d.ts

@@ -134,6 +134,7 @@ interface KnockoutBindingHandler {
     init? (element: any, valueAccessor: () => any, allBindingsAccessor: KnockoutAllBindingsAccessor, viewModel: any, bindingContext: KnockoutBindingContext): void;
     update? (element: any, valueAccessor: () => any, allBindingsAccessor: KnockoutAllBindingsAccessor, viewModel: any, bindingContext: KnockoutBindingContext): void;
     options?: any;
+    preprocess?: (value: string, name: string, addBindingCallback?: (name: string, value: string) => void) => string;
 }
 
 interface KnockoutBindingHandlers {