Prior to this release, the `javax.xml.transform.ErrorListener` specification defined that the default `ErrorListener` implementation reported warnings and errors to `System.err`, and `System.out` in some cases.
This requirement has been removed as of this release and the default `ErrorListener` now takes no action for warnings and recoverable errors; and in the case of a severe error, throws a `TransformerException`.

It is recommended that applications always register their own `ErrorListener` to ensure proper handling of warnings and errors.