code: def new_filehandlers_for_filetype(self, filetype_info, filenames, fh_kwargs=None):
          
          filename_iter = self.filename_items_for_filetype(filenames,
                                                           filetype_info)
          if self.filter_filenames:
              # preliminary filter of filenames based on start/end time
              # to reduce the number of files to open
              filename_iter = self.filter_filenames_by_info(filename_iter)
          filehandler_iter = self.new_filehandler_instances(filetype_info,
                                                            filename_iter,
                                                            fh_kwargs=fh_kwargs)
          filtered_iter = self.filter_fh_by_metadata(filehandler_iter)
          return list(filtered_iter)
docs: Create filehandlers for a given filetype.