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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def add_readgroups(job, bamfile, sample_type, univ_options, picard_options):
 """ Add read groups to the bam. :param dict bamfile: The input bam file :param str sample_type: Description of the sample to inject into the filename :param dict univ_options: Dict of universal options used by almost all tools :param dict picard_options: Options specific to picard :return: fsID for the output bam :rtype: toil.fileStore.FileID """

    work_dir = os.getcwd()
    input_files = {
        sample_type + '.bam': bamfile}
    get_files_from_filestore(job, input_files, work_dir, docker=True)
    parameters = ['AddOrReplaceReadGroups',
                  'CREATE_INDEX=false',
                  'I=/data/' + sample_type + '.bam',
                  'O=/data/' + sample_type + '_reheader.bam',
                  'SO=coordinate',
                  'ID=1',
                  ''.join(['LB=', univ_options['patient']]),
                  'PL=ILLUMINA',
                  'PU=12345',
                  ''.join(['SM=', sample_type.rstrip('_dna')])]
    docker_call(tool='picard', tool_parameters=parameters, work_dir=work_dir,
                dockerhub=univ_options['dockerhub'], java_xmx=univ_options['java_Xmx'],
                tool_version=picard_options['version'])
    output_file = job.fileStore.writeGlobalFile(
        '/'.join([work_dir, sample_type + '_reheader.bam']))
    # Delete the old bam file
    job.fileStore.deleteGlobalFile(bamfile)
    job.fileStore.logToMaster('Ran add_read_groups on %s:%s successfully'
                              % (univ_options['patient'], sample_type))
    return output_file