public abstract ResultT createUnmarshaller (ValidationEventHandler errorHandler)

When a JAXB provider needs to unmarshal a part of a document into an infoset representation, it first calls this method to create a Result object.

A JAXB provider will then send a portion of the XML into the given result. Such a portion always form a subtree of the whole XML document rooted at an element.

Parameters:
errorHandler     if any error happens between the invocation of this method and the invocation of getElement(Result), they must be reported to this handler. The caller must provide a non-null error handler. The Result object created from this method may hold a reference to this error handler.

Returns:  null if the operation fails. The error must have been reported to the error handler.