Changes the schema type associated with this data and returns a new XmlObject instance whose schemaType is the new type.
Returns the new XmlObject if the type change was successful, the old XmlObject if no changes could be made.
Certain type changes may be prohibited in the interior of an xml tree due to schema type system constraints (that is, due to a parent container within which the newly specified type is not permissible), but there are no constraints at the roottype changes are never prohibited at the root of an xml tree.
If the type change is allowed, then the new XmlObject should be used rather than the old one. The old XmlObject instance and any other XmlObject instances in the subtree are permanently invalidated and should not be used. (They will return XmlValueDisconnectedException if you try to use them.) If a type change is done on the interior of an Xml tree, then xsi:type attributes are updated as needed.