class_docstr: This class contains all the functions needed for supporting
  an accelerator family in Ray.
docstr: Get the number of accelerators of this family on ec2 instance with given type.
  
  Args:
      instance_type: The ec2 instance type.
      instances: Map from ec2 instance type to instance metadata returned by
          ec2 `describe-instance-types`.
  
  Returns:
      The number of accelerators of this family on the ec2 instance
      with given type.
      Return None if it's unknown.
docstr_tok: ["Get","the","number","of","accelerators","of","this","family","on","ec2","instance","with","given","type",".","Args",":","instance_type",":","The","ec2","instance","type",".","instances",":","Map","from","ec2","instance","type","to","instance","metadata","returned","by","ec2","`","describe-instance-types","`",".","Returns",":","The","number","of","accelerators","of","this","family","on","the","ec2","instance","with","given","type",".","Return","None","if","it","'s","unknown","."]
code: def get_ec2_instance_num_accelerators(
      instance_type: str, instances: dict
  ) -> Optional[int]:
      """Get the number of accelerators of this family on ec2 instance with given type.
  
      Args:
          instance_type: The ec2 instance type.
          instances: Map from ec2 instance type to instance metadata returned by
              ec2 `describe-instance-types`.
  
      Returns:
          The number of accelerators of this family on the ec2 instance
          with given type.
          Return None if it's unknown.
      """
      return None
  
file_path: ray/python/ray/_private/accelerators/accelerator.py
imports: from abc import ABC, abstractmethod
  from typing import Dict, Optional, List, Tuple
label_desc: Use image node_id 9 for calling the AcceleratorManager obj's underlying member method code with example usage: obj.get_ec2_instance_num_accelerators(instance_type, instances) and returns: None