public Identity withPrincipalId(String principalId) {
        setPrincipalId(principalId);
        return this;
    }
<p>
A unique identifier for the entity that made the call. For Time To Live, the principalId is
"dynamodb.amazonaws.com".
</p>

@param principalId
       A unique identifier for the entity that made the call. For Time To Live, the principalId is
       "dynamodb.amazonaws.com".
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-dynamodb/src/main/java/com/amazonaws/services/dynamodbv2/model/Identity.java