example.php

<?php

/**
 * Update example 8001
 */
function example_update_8001(&$sandbox) {
    print 'executing example update 8001';
}

/**
 * Update example 8002
 */
function example_update_8002(&$sandbox) {
    print 'executing example update 8002';
}

/**
 * Update example 8003
 */
function example_update_8003(&$sandbox) {
    print 'executing example update 8003';
}

samples.php

<?php

/**
 * Update samples 8001
 */
function samples_update_8001(&$sandbox) {
    print 'executing samples update 8001';
}