public void setEndpointId(String endpointId) {
        this.endpointId = endpointId;
    }
<p>
The unique identifier of the <code>AppInstanceUserEndpoint</code>.
</p>

@param endpointId
       The unique identifier of the <code>AppInstanceUserEndpoint</code>.
aws-java-sdk-chimesdkidentity/src/main/java/com/amazonaws/services/chimesdkidentity/model/DeregisterAppInstanceUserEndpointRequest.java