docs: def maskRegions(self, regions, verbose=False):
      """
        Mask the given regions in this sequence with Ns.
  
        :param region: iterable of regions to mask. Each region can be any object
                       with .start and .end attributes. Co-ords are zero based
                       and inclusive of both end points. Any other attributes
                       (e.g. chrom.) are ignored.
        :param verbose: print status messages to stderr if True
      """
      if verbose:
        pind = ProgressIndicator(totalToDo=len(regions),
                                 messagePrefix="completed",
                                 messageSuffix="of masking regions in " +
                                               self.name)
      for region in regions:
        self.maskRegion(region)
        if verbose:
          pind.done += 1
          pind.showProgress()