@Override
    public UpdateStateMachineAliasResult updateStateMachineAlias(UpdateStateMachineAliasRequest request) {
        request = beforeClientExecution(request);
        return executeUpdateStateMachineAlias(request);
    }
<p>
Updates the configuration of an existing state machine <a
href="https://docs.aws.amazon.com/step-functions/latest/dg/concepts-state-machine-alias.html">alias</a> by
modifying its <code>description</code> or <code>routingConfiguration</code>.
</p>
<p>
You must specify at least one of the <code>description</code> or <code>routingConfiguration</code> parameters to
update a state machine alias.
</p>
<note>
<p>
<code>UpdateStateMachineAlias</code> is an idempotent API. Step Functions bases the idempotency check on the
<code>stateMachineAliasArn</code>, <code>description</code>, and <code>routingConfiguration</code> parameters.
Requests with the same parameters return an idempotent response.
</p>
</note> <note>
<p>
This operation is eventually consistent. All <a>StartExecution</a> requests made within a few seconds use the
latest alias configuration. Executions started immediately after calling <code>UpdateStateMachineAlias</code> may
use the previous routing configuration.
</p>
</note>
<p>
<b>Related operations:</b>
</p>
<ul>
<li>
<p>
<a>CreateStateMachineAlias</a>
</p>
</li>
<li>
<p>
<a>DescribeStateMachineAlias</a>
</p>
</li>
<li>
<p>
<a>ListStateMachineAliases</a>
</p>
</li>
<li>
<p>
<a>DeleteStateMachineAlias</a>
</p>
</li>
</ul>

@param updateStateMachineAliasRequest
@return Result of the UpdateStateMachineAlias operation returned by the service.
@throws ValidationException
        The input does not satisfy the constraints specified by an Amazon Web Services service.
@throws InvalidArnException
        The provided Amazon Resource Name (ARN) is not valid.
@throws ResourceNotFoundException
        Could not find the referenced resource.
@throws ConflictException
        Updating or deleting a resource can cause an inconsistent state. This error occurs when there're
        concurrent requests for <a>DeleteStateMachineVersion</a>, <a>PublishStateMachineVersion</a>, or
        <a>UpdateStateMachine</a> with the <code>publish</code> parameter set to <code>true</code>.</p>
        <p>
        HTTP Status Code: 409
@throws StateMachineDeletingException
        The specified state machine is being deleted.
@sample AWSStepFunctions.UpdateStateMachineAlias
@see <a href="http://docs.aws.amazon.com/goto/WebAPI/states-2016-11-23/UpdateStateMachineAlias" target="_top">AWS
     API Documentation</a>
aws-java-sdk-stepfunctions/src/main/java/com/amazonaws/services/stepfunctions/AWSStepFunctionsClient.java