func NewSumBucketAggregation() *SumBucketAggregation {
	return &SumBucketAggregation{
		subAggregations: make(map[string]Aggregation),
		bucketsPaths:    make([]string, 0),
	}
}
NewSumBucketAggregation creates and initializes a new SumBucketAggregation.
package elastic
type SumBucketAggregation struct {
	format    string
	gapPolicy string
	subAggregations map[string]Aggregation
	meta            map[string]interface{}
	bucketsPaths    []string
}