public async Task BasicMapperTest <TK, TK1, TV, TV1>(
IKeyValueStore <TK, TV> underlyingStore,
ITypeMapper <TK1, TK> keyMapper,
ITypeMapper <TV1, TV> valueMapper,
IDictionary <TK1, TV1> items)
{
// Arrange
var keyValueMapper = new KeyValueStoreMapper <TK1, TK, TV1, TV>(underlyingStore, keyMapper, valueMapper);
// Act
KeyValuePair <TK1, TV1> item = items.First();
await keyValueMapper.Put(item.Key, item.Value);
// Assert
Option <TV1> value = await keyValueMapper.Get(item.Key);
Assert.True(value.HasValue);
Option <TV> underlyingValue = await underlyingStore.Get(keyMapper.From(item.Key));
Assert.True(underlyingValue.HasValue);
Assert.Equal(underlyingValue.OrDefault(), valueMapper.From(value.OrDefault()));
}