An Injector interface creates and maintains object graphs, tracks dependencies of each type, and uses bindings to inject them. Injectors keep a set of default bindings, from which they take configuration details for making and maintaining relationships between objects. Consider the following code, which will return an implementation of the AppConsumer class:

AppConsumer app = injector.getInstance(AppConsumer.class);

We can also get all the associated bindings with the injector by calling the Injector.getBindings() method, which returns a map containing binding objects:

Map<Key, Binding> bindings = injector.getBindings()

From this, we can say that each binding has a matching key object, which is internally made and kept by the Google Guice class.