docs: def main(argString=None):
      """The main function of the module.
  
      :param argString: the options.
  
      :type argString: list
  
      These are the steps:
  
      1. Prints the options.
      2. If there are ``summarized_intensities`` provided, reads the files
         (:py:func:`read_summarized_intensities`) and skips to step 7.
      3. Reads the ``bim`` file to get markers on the sexual chromosomes
         (:py:func:`read_bim`).
      4. Reads the ``fam`` file to get gender (:py:func:`read_fam`).
      5. Reads the file containing samples with sex problems
         (:py:func:`read_sex_problems`).
      6. Reads the intensities and summarizes them (:py:func:`read_intensities`).
      7. Plots the summarized intensities (:py:func:`plot_gender`).
  
      """
      # Getting and checking the options
      args = parseArgs(argString)
      checkArgs(args)
  
      data = None
      if args.summarized_intensities is None:
          # Reading the BIM file
          marker_names_chr = read_bim(args.bfile + ".bim")
  
          # Reading the FAM file
          sample_names_gender = read_fam(args.bfile + ".fam")
  
          # Reading the sex problem file
          sex_problems = read_sex_problems(args.sex_problems)
  
          # Reading the intensity file
          data = read_intensities(args.intensities, marker_names_chr,
                                  sample_names_gender, sex_problems)
  
      else:
          data = read_summarized_intensities(args.summarized_intensities)
  
      # Plot the gender
      plot_gender(data, args)