code: function(content) {
  			content = commentsUtils.strip(content);
  
  			// remove preprocessor string interpolations like #{var}
  			var stream = stringStream(content);
  			var replaceRanges = [];
  			var ch, ch2;
  
  			while ((ch = stream.next())) {
  				if (isQuote(ch)) {
  					// skip string
  					stream.skipString(ch)
  					continue;
  				} else if (ch === '#' || ch === '@') {
  					ch2 = stream.peek();
  					if (ch2 === '{') { // string interpolation
  						stream.start = stream.pos - 1;
  
  						if (stream.skipTo('}')) {
  							stream.pos += 1;
  						} else {
  							throw 'Invalid string interpolation at ' + stream.start;
  						}
  
  						replaceRanges.push([stream.start, stream.pos]);
  					}
  				}
  			}
  
  			return utils.replaceWith(content, replaceRanges, 'a');
  		}
docs: Sanitizes given CSS content: replaces content that may
  interfere with parsing (comments, interpolations, etc.)
  with spaces. Sanitized content MUST NOT be used for
  editing or outputting, it just simplifies searching
  @param  {String} content CSS content
  @return {String}