Collapsible Navs optionally accept the following props:

• collapsibleTrail / collapsible_trail, enables a vertical guideline to the left of the collapsible nav’s children
• iconRight optionally accepts an array of 2 icon values; the first is used as the default icon when the node is collapsed, the second is toggled when the node is expanded. If only 1 icon value is passed, the icon will not toggle between collapsible states.