core/play-guice/src/main/java/play/inject/guice/GuiceBuilder.java
public final Self configure(Config conf) {
    return newBuilder(delegate.configure(new play.api.Configuration(conf)));
  }
public final Self configure(Config conf) {
    return newBuilder(delegate.configure(new play.api.Configuration(conf)));
  }
Add additional configuration.

@param conf the configuration to add
@return a copy of this builder configured with the supplied configuration