class_docstr: Abstract class for implementing the strategy for launching the master instance of the cluster.
class_docstr_tok: ["Abstract","class","for","implementing","the","strategy","for","launching","the","master","instance","of","the","cluster","."]
docstr: The port where the master instance is started on. Will be None if not yet started.
  
  Returns:
      Optional[int]: The master port.
docstr_tok: ["The","port","where","the","master","instance","is","started","on",".","Will","be","None","if","not","yet","started",".","Returns",":","Optional","[","int","]",":","The","master","port","."]
code: def port(self) -> Optional[int]:
      """The port where the master instance is started on. Will be None if not yet started.
  
      Returns:
          Optional[int]: The master port.
      """
      return self._port
  
imports: import atexit
  import logging
  from subprocess import Popen
  from typing import Dict, List, Optional, Union
  from lazycluster.exceptions import LazyclusterError
  from lazycluster.runtime_mgmt import RuntimeGroup
label_desc: Use image node_id 2 for calling the MasterLauncher obj's underlying member method code with example usage: obj.port() and returns: self