class Sass::Tree::DirectiveNode

def to_s(tabs)
  if children.empty?
    value + ";"
  else
    result = if style == :compressed
               "#{value}{"
             else
               "#{'  ' * (tabs - 1)}#{value} {" + (style == :compact ? ' ' : "\n")
             end
    was_prop = false
    first = true
    children.each do |child|
      next if child.invisible?
      if style == :compact
        if child.is_a?(PropNode)
          result << "#{child.to_s(first || was_prop ? 1 : tabs + 1)} "
        else
          if was_prop
            result[-1] = "\n"
          end
          rendered = child.to_s(tabs + 1)
          rendered.lstrip! if first
          result << rendered
        end
        was_prop = child.is_a?(PropNode)
        first = false
      elsif style == :compressed
        result << (was_prop ? ";#{child.to_s(1)}" : child.to_s(1))
        was_prop = child.is_a?(PropNode)
      else
        result << child.to_s(tabs + 1) + "\n"
      end
    end
    result.rstrip + if style == :compressed
                      "}"
                    else
                      (style == :expanded ? "\n" : " ") + "}\n"
                    end
  end
end