Optional attributeOptional attributeSet to true if attributes is true or omitted and target's attribute value before the mutation needs to be recorded.
Optional attributesSet to true if mutations to target's attributes are to be observed. Can be omitted if attributeOldValue or attributeFilter is specified.
Optional characterSet to true if mutations to target's data are to be observed. Can be omitted if characterDataOldValue is specified.
Optional characterSet to true if characterData is set to true or omitted and target's data before the mutation needs to be recorded.
Optional childSet to true if mutations to target's children are to be observed.
Optional subtreeSet to true if mutations to not just target, but also target's descendants are to be observed.
Set to a list of attribute local names (without namespace) if not all attribute mutations need to be observed and attributes is true or omitted.