@Override
    public boolean equals(Object object) {
        if (this == object) return true;
        if (object == null || getClass() != object.getClass()) return false;
        var label = (LabelImpl) object;
        return isEqualTo(label);
    }
{@link Label} implementation used by {@link LabelCache}.

@author glebashnik
vespajlib/src/main/java/com/yahoo/tensor/impl/LabelImpl.java