https://github.com/google/guice/guice: Guice is a lightweight dependency injection framework for Java 6 and above (Google, Inc.) 
/*
 * Copyright (C) 2006 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.inject;


A module contributes configuration information, typically interface bindings, which will be used to create an Injector. A Guice-based application is ultimately composed of little more than a set of Modules and some bootstrapping code. 
Your Module classes can use a more streamlined syntax by extending AbstractModule rather than implementing this interface directly. 
In addition to the bindings configured via configure, bindings will be created for all methods annotated with @Provides. Use scope and binding annotations on these methods to configure the bindings. 
/**
 * A module contributes configuration information, typically interface bindings, which will be used
 * to create an {@link Injector}. A Guice-based application is ultimately composed of little more
 * than a set of {@code Module}s and some bootstrapping code.
 *
 * <p>Your Module classes can use a more streamlined syntax by extending {@link AbstractModule}
 * rather than implementing this interface directly.
 *
 * <p>In addition to the bindings configured via {@link #configure}, bindings will be created for
 * all methods annotated with {@literal @}{@link Provides}. Use scope and binding annotations on
 * these methods to configure the bindings.
 */
public interface Module {

  
Contributes bindings and other configurations for this module to binder. 
Do not invoke this method directly to install submodules. Instead use Binder.install(Module), which ensures that provider methods are discovered. 
/**
   * Contributes bindings and other configurations for this module to {@code binder}.
   *
   * <p><strong>Do not invoke this method directly</strong> to install submodules. Instead use
   * {@link Binder#install(Module)}, which ensures that {@link Provides provider methods} are
   * discovered.
   */
  void configure(Binder binder);
}