class Sass::Tree::Visitors::Convert

def visit_root(node)
  Sass::Util.enum_cons(node.children + [nil], 2).map do |child, nxt|
    visit(child) +
      if nxt &&
          (child.is_a?(Sass::Tree::CommentNode) &&
            child.line + child.lines + 1 == nxt.line) ||
          (child.is_a?(Sass::Tree::ImportNode) && nxt.is_a?(Sass::Tree::ImportNode) &&
            child.line + 1 == nxt.line) ||
          (child.is_a?(Sass::Tree::VariableNode) && nxt.is_a?(Sass::Tree::VariableNode) &&
            child.line + 1 == nxt.line)
        ""
      else
        "\n"
      end
  end.join.rstrip + "\n"
end