def fetch_data_async(blob, start_index, end_index, rpc=None):
  if isinstance(blob, BlobInfo):
    blob = blob.key()
  return blobstore.fetch_data_async(blob, start_index, end_index, rpc=rpc)
Fetch data for blob -- async version.
dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/ext/blobstore/blobstore.py/fetch_data_async