code: def main(argv):
      
      import argparse
      description = 'Uses Open Tree of Life web services to the MRCA for a set of OTT IDs.'
      parser = argparse.ArgumentParser(prog='ot-tree-of-life-mrca', description=description)
      parser.add_argument('ottid', nargs='*', type=int, help='OTT IDs')
      parser.add_argument('--subtree', action='store_true', default=False, required=False,
                          help='write a newick representation of the subtree rooted at this mrca')
      parser.add_argument('--induced-subtree', action='store_true', default=False, required=False,
                          help='write a newick representation of the topology of the requested taxa in the synthetic tree (the subtree pruned to just the queried taxa)')
      parser.add_argument('--details', action='store_true', default=False, required=False,
                          help='report more details about the mrca node')
      args = parser.parse_args(argv)
      id_list = args.ottid
      if not id_list:
          sys.stderr.write('No OTT IDs provided. Running a dummy query with 770302 770315\n')
          id_list = [770302, 770315]
      fetch_and_write_mrca(id_list, args.details, args.subtree, args.induced_subtree, sys.stdout, sys.stderr)
docs: This function sets up a command-line option parser and then calls fetch_and_write_mrca
      to do all of the real work.