code: public static Object getAggAttribute(Map<String,?> map ,String metrics,String attribute){
  		if(map != null) {
  			Map<String, Object> metrics_ = (Map<String, Object>) map.get(metrics);
  			if (metrics_ != null) {
  				return metrics_.get(attribute);
  			}
  		}
  		return null;
  	}
docs: {
  "key": "demoproject",
  "doc_count": 30,
  "successsums": {
  "doc_count_error_upper_bound": 0,
  "sum_other_doc_count": 0,
  "buckets": [
  {
  "key": 0,
  "doc_count": 30
  }
  ]
  }
  }
  
  @param map
  @param metrics successsums->doc_count_error_upper_bound
  successsums->sum_other_doc_count
  @param attribute maybe doc_count_error_upper_bound sum_other_doc_count buckets
  @return