class type processor = object .. end
The processor is the object that is notified when a new TCP connection
    is accepted. The processor has to include the protocol interpreter that
    reads and write data on this connection. See 
Defining Custom Processors
    for an example how to define a processor.
method process : when_done:(unit -> unit) ->
       container -> Unix.file_descr -> string -> unit
A user-supplied function that is called when a new socket connection
 is established. The function can now process the requests arriving
 over the connection. It is allowed to use the event system of the
 container, and to return immediately (multiplexing processor). It is 
 also allowed to process the requests synchronously and to first return
 to the caller when the connection is terminated. 
 The function must call when_done to indicate that it processed
 this connection completely.
 The string argument is the protocol name.
method supported_ptypes : parallelization_type list
The supported parallelization types