code: def _run_select_solution(ploidy_outdirs, work_dir, data):
      
      out_file = os.path.join(work_dir, "optimalClusters.txt")
      if not utils.file_exists(out_file):
          with file_transaction(data, out_file) as tx_out_file:
              ploidy_inputs = " ".join(["--ploidyRun%s=%s" % (p, d) for p, d in ploidy_outdirs])
              cmd = "titanCNA_selectSolution.R {ploidy_inputs} --outFile={tx_out_file}"
              do.run(cmd.format(**locals()), "TitanCNA: select optimal solution")
      return out_file
docs: Select optimal