// get and remove the element with minimal score, nil if the set is empty
//
// // Time complexity of this method is : O(log(N))
get and remove the element with minimal score, nil if the set is empty

Time complexity of this method is : O(log(N))
// get and remove the element with minimal score nil if the set is empty // // // Time complexity of this method is : O ( log ( N ))
func (this *SortedSet) PopMin() *SortedSetNodeKV {
	x := this.header.level[0].forward
	if x != nil {
		return this.Remove(x.key)
	}
	return nil
}
func ( this * SortedSet ) PopMin ( ) * SortedSetNodeKV { x := this . header . level [ 0 ] . forward if x != nil { return this . Remove ( x . key ) } return nil }
get and remove the element with minimal score, nil if the set is empty
get and remove the element with minimal score nil if the set is empty