code: def get_summary(url, spk=True):
      ''' simple function to retrieve the header of a BSP file and return SPK object'''
      # connect to file at URL
      bspurl = urllib2.urlopen(url)
      # retrieve the "tip" of a file at URL
      bsptip = bspurl.read(10**5) # first 100kB
      # save data in fake file object (in-memory)
      bspstr = StringIO(bsptip)
      # load into DAF object
      daf = DAF(bspstr)
      # return either SPK or DAF object
      if spk:
        # make a SPK object
        spk = SPK(daf)
        # return representation 
        return spk
      else:
        # return representation 
        return daf get_summary(url, spk=True):
      ''' simple function to retrieve the header of a BSP file and return SPK object'''
      # connect to file at URL
      bspurl = urllib2.urlopen(url)
      # retrieve the "tip" of a file at URL
      bsptip = bspurl.read(10**5) # first 100kB
      # save data in fake file object (in-memory)
      bspstr = StringIO(bsptip)
      # load into DAF object
      daf = DAF(bspstr)
      # return either SPK or DAF object
      if spk:
        # make a SPK object
        spk = SPK(daf)
        # return representation 
        return spk
      else:
        # return representation 
        return daf
docs: simple function to retrieve the header of a BSP file and return SPK object