code: function(content, ranges, ch, noRepeat) {
  			if (ranges.length) {
  				var offset = 0, fragments = [];
  				ranges.forEach(function(r) {
  					var repl = noRepeat ? ch : this.repeatString(ch, r[1] - r[0]);
  					fragments.push(content.substring(offset, r[0]), repl);
  					offset = r[1];
  				}, this);
  
  				content = fragments.join('') + content.substring(offset);
  			}
  
  			return content;
  		}
docs: Fills substrings in `content`, defined by given ranges,
  wich `ch` character
  @param  {String} content
  @param  {Array} ranges
  @return {String}