Merges variable declarations in a th:with attribute processor, taking the declarations in the target and combining them with the declarations in the source, overriding any same-named declarations in the target.
th:with
String
merge(String target, String source)
class Object
wait, wait, wait, equals, toString, hashCode, getClass, notify, notifyAll
Merge th:with attributes so that names from the source value overwrite the same names in the target value.
Groovy Documentation