docs: def paired_reader_from_bamfile(args,
                                 log,
                                 usage_logger,
                                 annotated_writer):
      '''Given a BAM file, return a generator that yields filtered, paired reads'''
      total_aligns = pysamwrapper.total_align_count(args.input_bam)
      bamfile_generator  = _bamfile_generator(args.input_bam)
      return _paired_reader(args.umt_length,
                            bamfile_generator,
                            total_aligns,
                            log,
                            usage_logger,
                            annotated_writer)