load() {
		const section_ids = this.cfgsections();
		const tasks = [];

		if (Array.isArray(this.children))
			for (let i = 0; i < section_ids.length; i++)
				tasks.push(this.loadChildren(section_ids[i])
					.then(Function.prototype.bind.call((section_id, set_values) =>  {
						for (let i = 0; i < set_values.length; i++)
							this.children[i].cfgvalue(section_id, set_values[i]);
					}, this, section_ids[i])));

		return Promise.all(tasks);
	}
Load the configuration covered by this section.

The `load()` function recursively walks the section element tree and
invokes the load function of each child option element.

@returns {Promise<void>}
Returns a promise resolving once the values of all child elements have
been loaded. The promise may reject with an error if any of the child
elements' load functions rejected with an error.