kahlan\Specification::_execute PHP Method

    protected function _execute()
    {
        static::$_instances[] = $this;
        $result = null;
        $spec = function () {
            $this->_expectations = [];
            $closure = $this->_closure;
            $result = $closure($this);
            foreach ($this->_expectations as $expectation) {
                $this->_passed = $expectation->passed() && $this->_passed;
            }
            array_pop(static::$_instances);
            return $result;
        };
        if (Suite::$PHP >= 7) {
            try {
                $result = $spec();
            } catch (Throwable $e) {
                $this->_passed = false;
                array_pop(static::$_instances);
                throw $e;
            }
        } else {
            try {
                $result = $spec();
            } catch (Exception $e) {
                $this->_passed = false;
                array_pop(static::$_instances);
                throw $e;
            }
        }
        return $result;
    }