PHPUnit_Framework_Assert::assertIsReadable PHP Method

    public static function assertIsReadable($filename, $message = '')
    {
        if (!is_string($filename)) {
            throw PHPUnit_Util_InvalidArgumentHelper::factory(1, 'string');
        }
        $constraint = new PHPUnit_Framework_Constraint_IsReadable();
        static::assertThat($filename, $constraint, $message);
    }

 public function isReadable()
 {
     $this->isExist();
     Assert::assertIsReadable($this->actual, $this->description);
     return $this;
 }