filter(section_id) {
		return true;
	}
Filter UCI section IDs to render.

The filter function is invoked for each UCI section ID of a given type
and controls whether the given UCI section is rendered or ignored by
the form section element.

The default implementation always returns `true`. User code or
classes extending `AbstractSection` may override this function with
custom implementations.

@abstract
@param {string} section_id
The UCI section ID to test.

@returns {boolean}
Returns `true` when the given UCI section ID should be handled and
`false` when it should be ignored.