'Initializes a new proxy.
module
a DB-API 2.0 module
poolclass
a Pool class, defaulting to QueuePool
Other parameters are sent to the Pool object\'s constructor.'

def __init__(self, module, poolclass=QueuePool, **kw):

    self.module = module
    self.kw = kw
    self.poolclass = poolclass
    self.pools = {}
    self._create_pool_mutex = threading.Lock()
