def selected_fields
      return @selected_fields unless @selected_fields.nil?

      fields = [*options[:select]].map { |f| f.split(',') }.flatten
      fields.concat(required_fields) if @fasta && !fields.empty?
      @selected_fields = fields.map { |f| glob_to_regex(f) }
    end
def selected_fields
      return @selected_fields unless @selected_fields.nil?

      fields = [*options[:select]].map { |f| f.split(',') }.flatten
      fields.concat(required_fields) if @fasta && !fields.empty?
      @selected_fields = fields.map { |f| glob_to_regex(f) }
    end
Returns an array of regular expressions containing all the selected fields