public UpdateVirtualGatewayRequest withClientToken(String clientToken) {
        setClientToken(clientToken);
        return this;
    }
<p>
Unique, case-sensitive identifier that you provide to ensure the idempotency of the request. Up to 36 letters,
numbers, hyphens, and underscores are allowed.
</p>

@param clientToken
       Unique, case-sensitive identifier that you provide to ensure the idempotency of the request. Up to 36
       letters, numbers, hyphens, and underscores are allowed.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-appmesh/src/main/java/com/amazonaws/services/appmesh/model/UpdateVirtualGatewayRequest.java