framework/db/PdoValueBuilder.php
public function build(ExpressionInterface $expression, array &$params = [])
    {
        $placeholder = static::PARAM_PREFIX . count($params);
        $params[$placeholder] = $expression;

        return $placeholder;
    }
public function build(ExpressionInterface $expression, array &$params = [])
    {
        $placeholder = static::PARAM_PREFIX . count($params);
        $params[$placeholder] = $expression;

        return $placeholder;
    }
{@inheritdoc}