def __init__(self, blob_key, buffer_size=131072, position=0):
    """Constructor.

    Args:
      blob_key: The blob key or string blob key to read from.
      buffer_size: The minimum size to fetch chunks of data from blobstore.
      position: The initial position in the file.
    """
    self.__blob_key = blob_key
    self.__buffer_size = buffer_size
    self.__buffer = ""
    self.__position = position
    self.__buffer_position = 0
    self.__eof = False
    self.__blob_info = None
Constructor.

    Args:
      blob_key: The blob key or string blob key to read from.
      buffer_size: The minimum size to fetch chunks of data from blobstore.
      position: The initial position in the file.
    
mapreduce/lib/blobstore/blobstore.py