/// Encapsulates waiting for any one of N resources to become available
/// A compact representation of a set of 32 booleans
/// Example device-drivers for USB devices
/// Example host-controller drivers
/// Abstraction over host-controller drivers
/// Encapsulating the layout of a USB bus
/// Main encapsulation of a USB bus and all its devices
/// Data representations straight from the USB standards
/// A mock host-controller driver, for writing unit tests