class_docstr: A class used to interface with the Ray control state.
  
  Attributes:
      global_state_accessor: The client used to query gcs table from gcs
          server.
class_docstr_tok: ["A","class","used","to","interface","with","the","Ray","control","state",".","Attributes",":","global_state_accessor",":","The","client","used","to","query","gcs","table","from","gcs","server","."]
code: def get_placement_group_by_name(
      self, placement_group_name, ray_namespace
  ):
      self._check_connected()
  
      placement_group_info = (
          self.global_state_accessor.get_placement_group_by_name(
              placement_group_name, ray_namespace
          )
      )
      if placement_group_info is None:
          return None
      else:
          placement_group_table_data = (
              gcs_pb2.PlacementGroupTableData.FromString(
                  placement_group_info
              )
          )
          return self._gen_placement_group_info(
              placement_group_table_data
          )
  
imports: import json
  import logging
  from collections import defaultdict
  from typing import Set
  from google.protobuf.json_format import MessageToDict
  import ray
  from ray._private.client_mode_hook import client_mode_hook
  from ray._private.resource_spec import NODE_ID_PREFIX, HEAD_NODE_RESOURCE_NAME
  from ray._private.utils import binary_to_hex, decode, hex_to_binary, validate_actor_state_name
  from ray._raylet import GlobalStateAccessor
  from ray.core.generated import common_pb2
  from ray.core.generated import gcs_pb2
  from ray.util.annotations import DeveloperAPI
label_desc: Use image node_id 12 for calling the GlobalState obj's underlying member method code with example usage: obj.get_placement_group_by_name(placement_group_name, ray_namespace) and returns: None, self