The saxon:next-in-chain attribute (XSLT-only) is used to direct the output to another stylesheet. The
value is the URL of a stylesheet that should be used to process the output stream. In this case
the output stream must always be pure XML, and attributes that control the format of the output
(e.g. method, cdata-section-elements, etc) will have no effect. The output of the second stylesheet
will be directed to the destination that would have been used for the first stylesheet if
no saxon:next-in-chain attribute were not present.
Supplying a zero-length string is equivalent to omitting the attribute, except that it can be used to override a previous setting.
