code: def reference_preprocessing(job, samples, config):
      
      job.fileStore.logToMaster('Processed reference files')
      config.fai = job.addChildJobFn(run_samtools_faidx, config.reference).rv()
      config.dict = job.addChildJobFn(run_picard_create_sequence_dictionary, config.reference).rv()
      job.addFollowOnJobFn(map_job, download_sample, samples, config)
docs: Spawn the jobs that create index and dict file for reference
  
      :param JobFunctionWrappingJob job: passed automatically by Toil
      :param Namespace config: Argparse Namespace object containing argument inputs
      :param list[list] samples: A nested list of samples containing sample information