Safari: null is not an object (evaluating '(i=n.anchorNode).nodeType')

        if (event.target === this.$editor[0]) {
                anchorNode = selection.anchorNode;
                if (anchorNode.nodeType === Node.TEXT_NODE) anchorNode = anchorNode.parentNode;
                
                // click occured before a `<kbd>` element
                if (anchorNode.nodeName === 'KBD') {
                    sibling = anchorNode.previousSibling;
                    if (sibling === null || sibling.textContent !== '\u200b') {
                        sibling = document.createTextNode('\u200b');
                        anchorNode.parentNode.insertBefore(sibling, anchorNode);
                    }
                    
                    this.caret.before(sibling);
                }
            }
            else if (event.target.nodeName === 'KBD') {
                var kbd = event.target;
                
                // check if the user clicked on a `<kbd>` element, but the browser placed the caret to the left
                anchorNode = selection.anchorNode;
                if (anchorNode.nodeType === Node.TEXT_NODE) {