C - The connection type, for the moment limited to URLConnection, this allows
the surrounding code to close the connection when the original request in interrupted.
public static interface MultiThreadURLFileSystemHelper.InterruptibleClosure<R,C extends java.net.URLConnection>
A closure for performing network operation in a context that they can be
interrupted. This code should be as short as possible, and take or require no
extra locks, as the code will be run on another thread.