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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 merge_mutect(job, perchrom_rvs):
 """ This module will merge the per-chromosome mutect files created by spawn_mutect into a genome vcf. It will make 2 vcfs, one for PASSing non-germline calls, and one for all calls. ARGUMENTS 1. perchrom_rvs: REFER RETURN VALUE of spawn_mutect() RETURN VALUES 1. output_files: <JSid for mutect_passing_calls.vcf> This module corresponds to node 11 on the tree """

    job.fileStore.logToMaster('Running merge_mutect')
    work_dir = job.fileStore.getLocalTempDir()
    # We need to squash the input dict of dicts to a single dict such that it can be passed to
    # get_files_from_filestore
    input_files = {filename: jsid for perchrom_files in perchrom_rvs.values()
                   for filename, jsid in perchrom_files.items()}
    input_files = get_files_from_filestore(job, input_files, work_dir, docker=False)
    chromosomes = [''.join(['chr', str(x)]) for x in range(1, 23) + ['X', 'Y']]
    with open('/'.join([work_dir, 'mutect_calls.vcf']), 'w') as mutvcf, \
            open('/'.join([work_dir, 'mutect_calls.out']), 'w') as mutout, \
            open('/'.join([work_dir, 'mutect_passing_calls.vcf']), 'w') as mutpassvcf:
        out_header_not_printed = True
        for chrom in chromosomes:
            with open(input_files[''.join(['mutect_', chrom, '.vcf'])], 'r') as mutfile:
                for line in mutfile:
                    line = line.strip()
                    if line.startswith('#'):
                        if chrom == 'chr1':
                            print(line, file=mutvcf)
                            print(line, file=mutpassvcf)
                        continue
                    else:
                        print(line, file=mutvcf)
                        line = line.split('\t')
                        if line[6] != 'REJECT':
                            print('\t'.join(line), file=mutpassvcf)
            with open(input_files[''.join(['mutect_', chrom,
                                           '.out'])], 'r') as mutfile:
                for line in mutfile:
                    line = line.strip()
                    if line.startswith('#'):
                        if chrom == 'chr1':
                            print(line, file=mutout)
                        continue
                    elif out_header_not_printed:
                        print(line, file=mutout)
                        out_header_not_printed = False
                    else:
                        print(line, file=mutout)
    output_file = job.fileStore.writeGlobalFile(mutpassvcf.name)
    return output_file