code: function MemChecker(d2, options) {
    this.d2 = d2
    this.log = this.d2.log.info.bind(this.d2.log)
    this.options = _.extend({}, DEFAULTS, options)
  
    this._shuttingDown = false
  
    setInterval(this.tick.bind(this), this.options.tickInterval * 1000)
  }
docs: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ MemChecker class  TODO: would be nice to print out some statistics, and have something like memwatch available via an ENV var toggle (ie. passing it as an option)