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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 sort_and_index_star(job, star_bams, univ_options, star_options):
 """ A wrapper for sorting and indexing the genomic star bam generated by run_star. It is required since run_star returns a dict of 2 bams :param dict star_bams: The bams from run_star :param dict univ_options: Dict of universal options used by almost all tools :param dict star_options: Options specific to star :return: Dict containing input bam and the generated index (.bam.bai) output_files: |- 'rna_transcriptome.bam': fsID +- 'rna_genome': |- 'rna_sorted.bam': fsID +- 'rna_sorted.bam.bai': fsID +- 'rnaChimeric.out.junction': fsID :rtype: dict """

    star_options['samtools']['n'] = star_options['n']
    sort = job.wrapJobFn(sort_bamfile, star_bams['rnaAligned.out.bam'], 'rna', univ_options,
                         samtools_options=star_options['samtools'],
                         disk=PromisedRequirement(sort_disk, star_bams['rnaAligned.out.bam']))
    index = job.wrapJobFn(index_bamfile, sort.rv(), 'rna', univ_options,
                          samtools_options=star_options['samtools'], sample_info='genome_sorted',
                          disk=PromisedRequirement(index_disk, sort.rv()))
    job.addChild(sort)
    sort.addChild(index)
    return {'rna_genome': index.rv(),
            'rna_transcriptome.bam': star_bams['rnaAligned.toTranscriptome.out.bam'],
            'rnaChimeric.out.junction': star_bams['rnaChimeric.out.junction']}