Definition
/**
* Create a CASE expression.
*
* @param non-empty-list<WhenClause> $whenClauses WHEN clauses
* @param null|Expression|string $elseResult ELSE result (optional)
* @param null|Expression|string $operand CASE operand for simple CASE (optional)
*/
case_when(array $whenClauses, Expression|string|null $elseResult, Expression|string|null $operand) : CaseExpression