code: def read_file(self, path):
      if os.path.exists(path):
          try:
              with open(path, "rb") as f:
                  return f.read()
          except IOError:
              # It may have been concurrently garbage collected by another
              # process
              pass
      return None
  
imports: from __future__ import print_function
  from collections import OrderedDict
  import os
  import sys
  import time
  from tempfile import NamedTemporaryFile
  from hashlib import sha1
  from metaflow.datastore import FlowDataStore
  from metaflow.datastore.content_addressed_store import BlobCache
  from metaflow.exception import MetaflowException
  from metaflow.metaflow_config import CLIENT_CACHE_PATH, CLIENT_CACHE_MAX_SIZE, CLIENT_CACHE_MAX_FLOWDATASTORE_COUNT, CLIENT_CACHE_MAX_TASKDATASTORE_COUNT
  from metaflow.plugins import DATASTORES
label_desc: Use image node_id 15 for calling the FileCache obj's underlying member method code with example usage: obj.read_file(path) and returns: None, f