class Sass::Engine

def import(files)
  nodes = []
  files.split(/,\s*/).each do |filename|
    engine = nil
    begin
      filename = self.class.find_file_to_import(filename, @options[:load_paths])
    rescue Exception => e
      raise SyntaxError.new(e.message, @line)
    end
    if filename =~ /\.css$/
      nodes << Tree::DirectiveNode.new("@import url(#{filename})", @options[:style])
    else
      File.open(filename) do |file|
        new_options = @options.dup
        new_options[:filename] = filename
        engine = Sass::Engine.new(file.read, @options)
      end
      engine.constants.merge! @constants
      engine.mixins.merge! @mixins
      begin
        root = engine.render_to_tree
      rescue Sass::SyntaxError => err
        err.add_backtrace_entry(filename)
        raise err
      end
      root.children.each do |child|
        child.filename = filename
        nodes << child
      end
      @constants = engine.constants
      @mixins = engine.mixins
    end
  end
  nodes
end