code: def swpool(agent, nnames, lenvals, names):
      
      agent = stypes.stringToCharP(agent)
      nnames = ctypes.c_int(nnames)
      lenvals = ctypes.c_int(lenvals)
      names = stypes.listToCharArray(names)
      libspice.swpool_c(agent, nnames, lenvals, names)
docs: Add a name to the list of agents to notify whenever a member of
      a list of kernel variables is updated.
  
      http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/swpool_c.html
  
      :param agent: The name of an agent to be notified after updates.
      :type agent: str
      :param nnames: The number of variables to associate with agent.
      :type nnames: int
      :param lenvals: Length of strings in the names array.
      :type lenvals: int
      :param names: Variable names whose update causes the notice.
      :type names: list of strs.