'A function which returns an iterator over dictionaries.
This is the only method used on import.
Args:
filename: The --filename argument passed in on the bulkloader command
line. This value is opaque to the bulkloader and thus could specify
any sort of descriptor for your generator.
bulkload_state: Passed in BulkloadConfig.BulkloadState object.
Returns:
An iterator describing an individual record. Typically a dictionary,
to be used with dict_to_model. Typically implemented as a generator.'

def generate_import_record(self, filename, bulkload_state):

    raise NotImplementedError
