code: function prefixBlock(prefix, block, skipEmpty) {
      var lines = block.split('\n');
      for (var i =0; i<lines.length; i++) {
        // Do not prefix empty lines
        if (lines[i].length === 0 && skipEmpty === true)
          continue;
        else
          lines[i] = prefix + lines[i];
      }
      return lines.join('\n');
    }
docs: Add prefix to the beginning of every line in block.