exists

abstract fun <X : Any> exists(prop: String, block: KNonNullTableEx<X>.() -> KNonNullExpression<Boolean>?): KNonNullExpression<Boolean>?
abstract fun <X : Any> exists(prop: ImmutableProp, block: KNonNullTableEx<X>.() -> KNonNullExpression<Boolean>?): KNonNullExpression<Boolean>?