docs: function FileFollower(file, options) {
    options = options || {};
    var self = this;
    this.file = file;
    this.currSize = fs.statSync(file).size;
    this.prevSize = this.currSize;
    this.interval = options.interval || 1000;
    batteries.fs.eachLine(file,
      { line: function(line) {
          self.emit('line', line);
        }
      , end: function() {
          self.startFollowing();
        }
      });
  }