function render( ctx ) {
	/* eslint-disable no-underscore-dangle */
	var props;
	var x;
	var y;

	props = {
		'namespace': 'http://www.w3.org/2000/svg',
		'attributes': {
			'stroke': '#aaa',
			'stroke-width': 1
		}
	};

	x = xAttr( ctx._orientation );
	y = yAttr( ctx._orientation );

	props.attributes[ x+'2' ] = ctx.tickDir * ctx._innerTickSize;
	props.attributes[ y+'1' ] = 0.5;
	props.attributes[ y+'2' ] = 0.5;

	debug( 'Generating a virtual DOM tree (%s) with properties: %s.', ELEMENT, JSON.stringify( props ) );

	return h( ELEMENT, props, [] );
}
Renders a tick line.

@private
@param {Object} ctx - context
@returns {VTree} virtual tree