docs: def _get_clearinghouse_vessel_handle(vesselhandle):
    """
    <Purpose>
      Acquires the unique vessel identifier for a given vesselhandle.
  
    <Arguments>
      vesselhandle:
        A vessel handle expressed in the form node_ip:node_port:vesselname.
  
    <Side Effects>
      Opens a connection to the vessel to retrieve its nodekey.
  
    <Exceptions>
      None
  
    <Returns>
      A list of Clearinghouse vesselhandles for each vessel.
  
    """
    host, portstring, vesselname = vesselhandle.split(':')
    port = int(portstring)
  
    # get information about the node's vessels
    try:
      nodehandle = nmclient.nmclient_createhandle(host, port,
        timeout=seash_global_variables.globalseashtimeout)
  
    except NMClientException,e:
      return (False, str(e))
  
    try:
      # We need to get the nodekey on this vessel
      vesseldict = nmclient.nmclient_getvesseldict(nodehandle)
    except NMClientException,e:
      return (False, str(e))
    finally:
      nmclient.nmclient_destroyhandle(nodehandle)
  
    nodekeystr = rsa.rsa_publickey_to_string(vesseldict['nodekey'])
    return (True, nodekeystr+':'+vesselname)