anchor.diff:  The ((_pair_ protocol)) implements a peer-to-peer pattern, where
   relationships between peers are one-to-one.
   
  -Version 1 of this protocol supports an optional ((_polyamorous_ mode)) where a
  -peer can maintain multiple partnerships.
  -Using this mode requires some additional sophistication in the application.
  -
   === Socket Operations
   
   The xref:nng_pair_open.3.adoc[`nng_pair_open()`] functions create a _pair_ socket.
  
positive.code: = nng_pair(7)
  //
  // Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
  // Copyright 2018 Capitar IT Group BV <info@capitar.com>
  //
  // This document is supplied under the terms of the MIT License, a
  
negative.code: 
  Version 1 of the protocol offers improved protection against loops when
  used with xref:nng_device.3.adoc[`nng_device()`].
  
  NOTE: Version 1 of this protocol is considered experimental at this time.
  
  === Polyamorous Mode
  
  CAUTION: Polyamorous mode was provided as an experiment, and that experiment
  is deemed to have failed.
  Thus use of this mode is discouraged.
  In particular, the design cannot function over
  xref:nng_device.3.adoc[device] proxies.
  Consequently, this mode may be removed in a future release.
  
  Normally pair sockets are for one-to-one communication, and a given peer
  will reject new connections if it already has an active connection to another
  