@Override
    public BucketValue copy() {
        return new BucketValue(getLabel(), getLevelOrNull(), getFrom().copy(), getTo().copy());
    }
This class represents a bucket in a {@link PredefinedFunction}. The generic T is the data type of the range values
'from' and 'to'. The range is inclusive-from and exclusive-to. All supported data types are represented as subclasses
of this.

@author Simon Thoresen Hult
container-search/src/main/java/com/yahoo/search/grouping/request/BucketValue.java