def auth_sub_string_from_body(http_body):
  for response_line in http_body.splitlines():
    if response_line.startswith('Token='):
      # Strip off Token= and return the token value string.
      return response_line[6:]
  return None
Fetches the authenticated Facebook user.
dataset/ETHPy150Open acil-bwh/SlicerCIP/Scripted/attic/PicasaSnap/gdata/gauth.py/auth_sub_string_from_body--crossover with--dataset/ETHPy150Open D-L/SimpleBookMarks/src/tornado/auth.py/FacebookMixin.get_authenticated_user