docstr: helper function to hold execution until some workers are active
  
  Parameters
  ----------
  min_n_workers: int
          minimum number of workers present before the run starts         
docstr_tok: ["helper","function","to","hold","execution","until","some","workers","are","active","Parameters","--","--","--","--","--","min_n_workers",":","int","minimum","number","of","workers","present","before","the","run","starts"]
code: def wait_for_workers(self, min_n_workers=1):
      """
      helper function to hold execution until some workers are active
  
      Parameters
      ----------
      min_n_workers: int
              minimum number of workers present before the run starts
      """
  
      self.logger.debug("wait_for_workers trying to get the condition")
      with self.thread_cond:
          while self.dispatcher.number_of_workers() < min_n_workers:
              self.logger.debug(
                  "HBMASTER: only %i worker(s) available, waiting for at least %i."
                  % (self.dispatcher.number_of_workers(), min_n_workers)
              )
              self.thread_cond.wait(1)
              self.dispatcher.trigger_discover_worker()
  
      self.logger.debug("Enough workers to start this run!")
  
imports: import os
  import threading
  import time
  import math
  import pdb
  import copy
  import logging
  import numpy
  from hpbandster.core.dispatcher import Dispatcher
  from hpbandster.core.result import Result
  from hpbandster.core.base_iteration import WarmStartIteration
label_desc: Use image node_id 3 for calling the Master obj's underlying member method code with example usage: obj.wait_for_workers(min_n_workers) without return types