class Sass::Tree::Visitors::ToCss

def output(s)

accordingly.
Add `s` to the output string and update the line and offset information
def output(s)
  if @lstrip
    s = s.gsub(/\A\s+/, "")
    @lstrip = false
  end
  newlines = s.count(NEWLINE)
  if newlines > 0
    @line += newlines
    @offset = s[s.rindex(NEWLINE)..-1].size
  else
    @offset += s.size
  end
  @result << s
end