docs: function(cpu) {
          if (!isNaN(cpu)) {
              var cpuHistory = this.get('cpu');
              if (!cpuHistory) {
                  cpuHistory = [];
                  this.set('cpu', cpuHistory);
              }
  
              cpuHistory.push(cpu);
              while (cpuHistory.length > this._statHistory) {
                  cpuHistory.shift();
              }
  
              var avg = 0;
              cpuHistory.filter(function(f) {
                  return f !== null;
              }).forEach(function(f) {
                  avg += f;
              });
              avg /= cpuHistory.length;
              this.set({
                  avgCpu: Math.round(avg)
              });
          }
      }