package async_extra

close t closes the connection. The returned deferred becomes determined once any resources needed to maintain the connection have been released.

is_closed t returns true if close has ever been called (even if the returned deferred has not yet been fulfilled).

Note that some modules implementing Closable may call close internally upon noticing that the connection was closed by the other side. The interface of such a module ought to say that this is the case.

close_finished t becomes determined at the same time as the result of the first call to close. close_finished differs from close in that it does not have the side effect of initiating a close.