public String getDomain() {
        return this.domain;
    }
<p>
The domain name for the custom domain that hosts the sign-up and sign-in pages for your application. One example
might be <code>auth.example.com</code>.
</p>
<p>
This string can include only lowercase letters, numbers, and hyphens. Don't use a hyphen for the first or last
character. Use periods to separate subdomain names.
</p>

@return The domain name for the custom domain that hosts the sign-up and sign-in pages for your application. One
        example might be <code>auth.example.com</code>. </p>
        <p>
        This string can include only lowercase letters, numbers, and hyphens. Don't use a hyphen for the first or
        last character. Use periods to separate subdomain names.
aws-java-sdk-cognitoidp/src/main/java/com/amazonaws/services/cognitoidp/model/UpdateUserPoolDomainRequest.java