class Sass::Tree::DirectiveNode

def to_src(tabs, opts, fmt)

Other tags:
    See: Node#to_src -
def to_src(tabs, opts, fmt)
  res = "#{'  ' * tabs}#{value}"
  return res + "#{semi fmt}\n" unless has_children
  res + children_to_src(tabs, opts, fmt) + "\n"
end