class_docstr: Mapper that leverages python's multiprocessing.
      
docstr: Create a new server if one isn't already initialized
docstr_tok: ["Create","a","new","server","if","one","is","n't","already","initialized"]
code: def _serve(self, nodes=None):  # XXX: should be STATE method; use id
      """Create a new server if one isn't already initialized"""
      if nodes is None:
          nodes = self.__nodes
      _pool = __STATE.get(self._id, None)
      if (
          not _pool
          or nodes != _pool.__nodes
          or self._kwds != _pool._kwds
      ):
          self._clear()
          _pool = Pool(nodes, **self._kwds)
          _pool.__nodes = nodes
          _pool._kwds = self._kwds
          __STATE[self._id] = _pool
      return _pool
  
imports: from pathos.abstract_launcher import AbstractWorkerPool
  from pathos.helpers.mp_helper import starargs
  from pathos.helpers import cpu_count, freeze_support, ProcessPool
  import warnings
  import sys
  from pathos.helpers import ThreadPool
  from pathos.threading import ThreadPool
label_desc: Use image node_id 2 for calling the ProcessPool obj's underlying member method code with example usage: obj._serve(nodes) and returns: _pool