Each package defines a number of classes, interfaces, exceptions,
and errors. For example, the java.net package contains these,
interfaces, classes, and exceptions:
ContentHandlerFactoryFileNameMapSocketImplFactoryURLStreamHandlerFactoryContentHandlerDatagramPacketDatagramSocketDatagramSocketImplHttpURLConnectionInetAddressMulticastSocketServerSocketSocketSocketImplURLURLConnectionURLEncoderURLStreamHandlerBindExceptionConnectExceptionMalformedURLExceptionNoRouteToHostExceptionProtocolExceptionSocketExceptionUnknownHostExceptionUnknownServiceException