public function testPrecondition_fail()
{
$this->setExpectedException('Wikimedia\\Assert\\PreconditionException');
Assert::precondition(false, 'test');
}
/**
* Replace the element at position $idx in the BalanceStack with $elt.
* @param int $idx
* @param BalanceElement $elt
*/
public function replaceAt($idx, BalanceElement $elt)
{
Assert::precondition($this->elements[$idx]->parent !== 'flat', 'Replaced element should not have already been flattened.');
Assert::precondition($elt->parent !== 'flat', 'New element should not have already been flattened.');
$this->elements[$idx] = $elt;
if ($idx === count($this->elements) - 1) {
$this->currentNode = $elt;
}
}
