def process_with_filter(input, filter_class)
      filter = filter_class.new

      output = MemoryFileWrapper.new("/output", input.path, "UTF-8")
      output.create { filter.generate_output([input], output) }

      output
    end
def process_with_filter(input, filter_class)
      filter = filter_class.new

      output = MemoryFileWrapper.new("/output", input.path, "UTF-8")
      output.create { filter.generate_output([input], output) }

      output
    end
@private

 Process an individual file with a filter.