def convert! (*filters)
      filters.flatten.each do |filter|
        f = Filters.resolve!(filter)
        @tokens.map! { |t| f.apply(t) }
      end

      self
    end
def convert! (*filters)
      filters.flatten.each do |filter|
        f = Filters.resolve!(filter)
        @tokens.map! { |t| f.apply(t) }
      end

      self
    end
Converts all string values according to the given filter(s).