# File lib/sass/script/functions.rb, line 1413
    def unquote(string)
      unless string.is_a?(Sass::Script::Value::String)
        # Don't warn multiple times for the same source line.
        # rubocop:disable GlobalVars
        $_sass_warned_for_unquote ||= Set.new
        frame = environment.stack.frames.last
        key = [frame.filename, frame.line] if frame
        return string if frame && $_sass_warned_for_unquote.include?(key)
        $_sass_warned_for_unquote << key if frame
        # rubocop:enable GlobalVars

        Sass::Util.sass_warn("DEPRECATION WARNING: Passing \#{string.to_sass}, a non-string value, to unquote()\nwill be an error in future versions of Sass.\n\#{environment.stack.to_s.gsub(/^/, ' ' * 8)}\n".strip)
        return string
      end

      string.check_deprecated_interp
      return string if string.type == :identifier
      identifier(string.value)
    end