@Override
 public boolean equals(Object obj) {
   if (this == obj) {
     return true;
   }
   if (obj == null) {
     return false;
   }
   if (getClass() != obj.getClass()) {
     return false;
   }
   CpuStats other = (CpuStats) obj;
   if (cpuUsage == null) {
     if (other.cpuUsage != null) {
       return false;
     }
   } else if (!cpuUsage.equals(other.cpuUsage)) {
     return false;
   }
   if (systemCpuUsage == null) {
     if (other.systemCpuUsage != null) {
       return false;
     }
   } else if (!systemCpuUsage.equals(other.systemCpuUsage)) {
     return false;
   }
   return true;
 }
 @Override
 public int hashCode() {
   final int prime = 31;
   int result = 1;
   result = prime * result + (cpuUsage == null ? 0 : cpuUsage.hashCode());
   result = prime * result + (systemCpuUsage == null ? 0 : systemCpuUsage.hashCode());
   return result;
 }