docs: def get_filename(disposition):
      """Parse Content-Disposition header to pull out the filename bit.
  
      See: http://tools.ietf.org/html/rfc2616#section-19.5.1
  
      """
      if disposition:
          params = [param.strip() for param in disposition.split(';')[1:]]
          for param in params:
              if '=' in param:
                  name, value = param.split('=', 1)
                  if name == 'filename':
                      return value.strip('"')