def get(cls, blob_keys):
    """Retrieve BlobInfo by key or list of keys.

    Args:
      blob_keys: A key or a list of keys.  Keys may be instances of str,
      unicode and BlobKey.

    Returns:
      A BlobInfo instance associated with provided key or a list of BlobInfo
      instances if a list of keys was provided.  Keys that are not found in
      Blobstore return None as their values.
    """
    blob_keys = cls.__normalize_and_convert_keys(blob_keys)
    try:
      entities = datastore.Get(blob_keys)
    except datastore_errors.EntityNotFoundError:
      return None
    if isinstance(entities, datastore.Entity):
      return BlobInfo(entities)
    else:
      references = []
      for entity in entities:
        if entity is not None:
          references.append(BlobInfo(entity))
        else:
          references.append(None)
      return references
Retrieve BlobInfo by key or list of keys.

    Args:
      blob_keys: A key or a list of keys.  Keys may be instances of str,
      unicode and BlobKey.

    Returns:
      A BlobInfo instance associated with provided key or a list of BlobInfo
      instances if a list of keys was provided.  Keys that are not found in
      Blobstore return None as their values.
    
mapreduce/lib/blobstore/blobstore.py