A mutation record describing a change to the text content of a CharacterData node (text, comment, CDATA section).
CharacterData
The node data before the change, if the observer requested it (characterDataOldValue); null otherwise. Always null for records from createDOMMutationObservable.
characterDataOldValue
null
The node whose data changed.
Discriminant of the MutationRecord union.
A mutation record describing a change to the text content of a
CharacterDatanode (text, comment, CDATA section).