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