public function testGetValueWithNonExistentKey()
 {
     // Arrange.
     $stringKey = 'foo';
     $result = new Result([]);
     $this->mockDynamoDbClient->expects($this->once())->method('getItem')->with(['TableName' => $this->storeKeyTableName, 'Key' => [$this->storeKeyAttribute => ['S' => $stringKey]]])->willReturn($result);
     // Act.
     $actual = $this->storeKeyClient->getValue($stringKey);
     // Assert.
     $this->assertFalse($actual);
 }