def annotate(filename)
      engine = Sass::Engine.new(IO.read(filename), options.merge(:syntax=>guess_syntax(filename)))
      tree = engine.to_tree
      tree.perform!(Sass::Environment.new)
      resolve_rules tree
      @rows = to_rows(tree)
    end
def annotate(filename)
      engine = Sass::Engine.new(IO.read(filename), options.merge(:syntax=>guess_syntax(filename)))
      tree = engine.to_tree
      tree.perform!(Sass::Environment.new)
      resolve_rules tree
      @rows = to_rows(tree)
    end
Annotate the named file. Sets and returns rows.