code: def size_file(self, path):
      import google.api_core.exceptions
  
      try:
          blob = self.root_client.get_blob_client(path)
          blob.reload()
          return blob.size
      except google.api_core.exceptions.NotFound:
          return None
  
imports: import json
  import os
  import shutil
  import uuid
  from concurrent.futures import as_completed
  from tempfile import mkdtemp
  from metaflow.datastore.datastore_storage import DataStoreStorage, CloseAfterUse
  from metaflow.exception import MetaflowInternalError
  from metaflow.metaflow_config import DATASTORE_SYSROOT_GS, ARTIFACT_LOCALROOT, GS_STORAGE_WORKLOAD_TYPE
  from metaflow.plugins.gcp.gs_storage_client_factory import get_gs_storage_client
  from metaflow.plugins.gcp.gs_utils import check_gs_deps, parse_gs_full_path, process_gs_exception
  from metaflow.plugins.storage_executor import StorageExecutor, handle_executor_exceptions
label_desc: Use image node_id 6 for calling the GSStorage obj's underlying member method code with example usage: obj.size_file(path) and returns: blob, None