setFocusToFirstNode () {
      if (this.config.disableFocus) return

      const focusableNodes = this.getFocusableNodes()

      // no focusable nodes
      if (focusableNodes.length === 0) return

      // remove nodes on whose click, the modal closes
      // could not think of a better name :(
      const nodesWhichAreNotCloseTargets = focusableNodes.filter(node => {
        return !node.hasAttribute(this.config.closeTrigger)
      })

      if (nodesWhichAreNotCloseTargets.length > 0) nodesWhichAreNotCloseTargets[0].focus()
      if (nodesWhichAreNotCloseTargets.length === 0) focusableNodes[0].focus()
    }
Tries to set focus on a node which is not a close trigger
if no other nodes exist then focuses on first close trigger