How to configure a custom error page for the path which is served through EAP 7 file handler

Issue

I'm using <file> handler to serve static contents like the following:

    <subsystem xmlns="urn:jboss:domain:undertow:3.1">
        ...
        <server name="default-server">
            <http-listener name="default" socket-binding="http" redirect-socket="https"></http>
            <host name="default-host" alias="localhost">
                <location name="/" handler="welcome-content"></location>
                <location name="/example" handler="my-static-contents"></location> <!-- added this -->
                ...
            </host>
        </server>
        ...
        <handlers>
            <file name="welcome-content" path="${jboss.home.dir}/welcome-content"></file>
            <file name="my-static-contents" path="/path/to/custom/static-content/"></file> <!-- added this -->
        </handlers>
        ...
    </subsystem>

How do I specify a custom error page for the <file> handler? For example, I would like to return custom "404 Not Found" error page when the client access non-existent URI under the path. Currently, it returns Undertow's default error page.