public Condition removeCondition(int i) {
        Condition condition = conditions.remove(i);
        condition.setParent(null);
        return condition;
    }
Returns the condition at the given index

@param i the 0-base index
@return the removed condition
@throws IndexOutOfBoundsException if there is no condition at this index
container-search/src/main/java/com/yahoo/prelude/semantics/rule/CompositeCondition.java