docs: def createSummaryFile(results, maf, prefix):
      """Creat the final summary file containing plate bias results.
  
      :param results: the list of all the significant results.
      :param maf: the minor allele frequency of the significant results.
      :param prefix: the prefix of all the files.
  
      :type results: list
      :type maf: dict
      :type prefix: str
  
      """
      o_filename = prefix + ".significant_SNPs.summary"
      try:
          with open(o_filename, "w") as o_file:
              print >>o_file, "\t".join(("chrom", "pos", "name", "maf", "p",
                                         "odds", "plate"))
              for row in results:
                  print >>o_file, "\t".join((
                      row.chrom,
                      row.pos,
                      row.name,
                      maf.get(row.name, "N/A"),
                      row.p,
                      row.odds,
                      row.plate,
                  ))
  
      except IOError:
          msg = "{}: cannot write file".format(o_filename)
          raise ProgramError(msg)