In case you want to include a function or variable eliminated by Rollup.js treeshaking.

loadModule.js

export var loadModule = function(module) {
    // Trick Rollup.js to keep JavaScript.
    let obj = {
        method: function() {}
    };
    obj.method(module);
};


/* Example usage
 * =============
import { loadModule } from './loadModule';
import { my_dom_function } from './utils';

loadModule(my_dom_function);
*/