docs: def adjustPoolSize(self, newsize):
          """
          Change the target pool size. If we have too many connections already,
          ask some to finish what they're doing and die (preferring to kill
          connections to the node that already has the most connections). If
          we have too few, create more.
          """
  
          if newsize < 0:
              raise ValueError("pool size must be nonnegative")
          self.log("Adjust pool size from %d to %d." % (self.target_pool_size, newsize))
          self.target_pool_size = newsize
          self.kill_excess_pending_conns()
          self.kill_excess_conns()
          self.fill_pool()