/**
  * Test 'touch' method.
  */
 public function testTouch()
 {
     $mock = new MemcachedMock();
     $this->assertFalse($mock->touch('a', 765));
     $this->assertFalse($mock->touch(null, 765));
     $testKey = 'abc123';
     $testValue = 'some value';
     $mock = $this->getMemcachedMock();
     $expiryStart = time() + 10;
     $this->assertTrue($mock->set($testKey, $testValue, $expiryStart));
     $this->assertSame($expiryStart, $mock->getExpiry($testKey));
     $this->assertSame($testValue, $mock->get($testKey));
     $expiry1 = time() + 10;
     $this->assertTrue($mock->touch($testKey, $expiry1));
     $this->assertSame($expiry1, $mock->getExpiry($testKey));
     $expiry2 = 5;
     $this->assertTrue($mock->touch($testKey, $expiry2));
     $this->assertSame(time() + $expiry2, $mock->getExpiry($testKey));
     $mock->setThrowExceptionsOnFailure(false);
     $this->assertFalse($mock->touch('does_not_exists', 765));
     $this->assertFalse($mock->touch($testKey, 'invalid_expiry'));
     $this->assertFalse($mock->touch(null, 1));
 }