GET request providing only partitionKey on a table with a defined sortKey results in error

[bwermes]

Describe the bug When performing a GET request providing only the partitionKey against a table that also contains a sortKey results in an error: please provide the sort key for the attribute name

My table contains

To Reproduce Steps to reproduce the behavior:

1. Create a table with a PartitionKey and a SortKey: `@Model({tableName: 'Sample'}) export class className{ @PartitionKey() pk: string

   @SortKey() sk: string

   name: string;

   public constructor(init?: Partial<className>) { Object.assign(this, init); } }`

2. Perform a GET request against that table: const sample = await new DynamoStore(Sample).get('myPartitionKey');

3. Observe the error

Expected behavior The GET method provides for the SortKey as optional. Other Dynamo libraries allow you to query a single record by PartitionKey only, returning the first record if multiple exist.