@Override
    public ChoiceExpression convertChildren(ExpressionConverter converter) {
        return new ChoiceExpression(asList().stream().map(choice -> converter.branch().convert(choice)).toList());
    }
An expression which returns the value of the first of a list of subexpressions which
returns a non-null value.

Syntax: sub-expression1 || sub-expression2 || ...

@author bratseth
indexinglanguage/src/main/java/com/yahoo/vespa/indexinglanguage/expressions/ChoiceExpression.java