PHPUnit_Framework_Assert::arrayHasKey PHP Method

    public static function arrayHasKey($key)
    {
        return new PHPUnit_Framework_Constraint_ArrayHasKey($key);
    }

 /**
  * @covers PHPUnit_Framework_Constraint_ArrayHasKey
  * @covers PHPUnit_Framework_Constraint_Not
  * @covers PHPUnit_Framework_Assert::arrayHasKey
  * @covers PHPUnit_Framework_Assert::logicalNot
  */
 public function testConstraintArrayNotHasKey2()
 {
     $constraint = PHPUnit_Framework_Assert::logicalNot(PHPUnit_Framework_Assert::arrayHasKey(0));
     try {
         $constraint->fail(array(0), 'custom message', TRUE);
     } catch (PHPUnit_Framework_ExpectationFailedException $e) {
         $this->assertEquals("custom message\nFailed asserting that an array does not have the key <integer:0>.", $e->getDescription());
         return;
     }
     $this->fail();
 }