# File lib/nanoc/extra/validators/w3c.rb, line 13
    def run
      args = []
      types = @types.dup
      args << 'html' if types.delete(:html)
      args << 'css'  if types.delete(:css)
      unless types.empty?
        raise Nanoc::Errors::GenericTrivial, "unknown type(s) specified: #{types.join(', ')}"
      end

      Nanoc::CLI.run([ 'check', args ].flatten)
    end