code: public static SourceSnippet callGetter(final Key<?> key) {
      return new SourceSnippet() {
        public String getSource(InjectorWriteContext writeContext) {
          return writeContext.callGetter(key);
        }
      };
    }
docs: Creates a snippet that evaluates to an injected instance of the given key
  in the current {@link GinjectorBindings}.