public java.util.Map<String, String> getExternalIdProperty() {
        return externalIdProperty;
    }
<p>
A mapping of external IDs to property names. External IDs uniquely identify properties from external data stores.
</p>

@return A mapping of external IDs to property names. External IDs uniquely identify properties from external data
        stores.
aws-java-sdk-iottwinmaker/src/main/java/com/amazonaws/services/iottwinmaker/model/EntityPropertyReference.java