class type server_endpoint_acceptor =object..end
This class type is for service providers that listen for connections.
 By calling accept, one gets an engine that waits for the next
 connection, and establishes it.
There are services that can only accept one connection for a 
 certain contact address. In this case accept must only be called
 once. Normally, services can accept any number of connections
 (multiplexing), and it is allowed to call accept again after
 the previous accept engine was successful.
method server_address : Uq_engines.connect_addressThe contact address under which the clients can establish new connections with this server.
method multiple_connections : boolWhether it is possible to accept multiple connections
method accept : unit -> (Unix.file_descr * Uq_engines.inetspec option) Uq_engines.engineInstantiates an engine that accepts connections on the listening endpoint.
If the connection is successfully established, the state of the engine
 changes to `Done(fd,addr) where fd is the connected file descriptor,
 and where addr (if not-None) is the endpoint address of the 
 connecting client (from the server's perspective). Such addresses are
 only supported for Internet endpoints. If a proxy is used to accept
 the connections, the returned address is that from the proxy's 
 view, and usually different from what Unix.getpeername returns.
The close-on-exec flag of the created endpoint descriptor is always set. The endpoint descriptor is always in non-blocking mode.
It is allowed to shut down fd for sending, and it is required to
 close fd after all data transfers have been performed.
A call of accept allows it only to establish one connection at a time.
 However, it is allowed to call accept several times to accept several
 connections, provided the acceptor supports this (returned by
 multiple_connections). It is only allowed to call accept again
 when the previous engine was successful.
method shut_down : unit -> unitThe server endpoint is shut down such that no further connections
 are possible. It is required to call this method even for acceptors
 that do not support multiple connections. It is also required to
 call this method when an accept was not successful.
If there is a engine waiting for connections, it is aborted.