docs: static Set<String> extractPortKeys(Configuration config) {
  		final LinkedHashSet<String> tmPortKeys = new LinkedHashSet<>(TM_PORT_KEYS);
  
  		final String portKeys = config.getString(PORT_ASSIGNMENTS);
  
  		if (portKeys != null) {
  			Arrays.stream(portKeys.split(","))
  				.map(String::trim)
  				.peek(key -> LOG.debug("Adding port key {} to mesos request"))
  				.forEach(tmPortKeys::add);
  		}
  
  		return Collections.unmodifiableSet(tmPortKeys);
  	}