Returns the next or previous sibling that is not a text node. Please note: the behavior with comments is subject to change. Currently, it will return a comment or other nodes if it is in the tree (if you enabled it with Document.enableAddingSpecialTagsToDom or Document.parseSawComment) and not if you didn't, but the implementation will probably change at some point to skip them regardless.

Equivalent to previousSibling/nextSibling.

Please note it may return null.