An empty method may be confusing. Add a nested comment explaining why this method is empty, throw an UnsupportedOperationException or complete the implementation.
You may want to add a default case to this switch to deal with unforseen inputs.
Default branches should deal with the unexpected. At a minimum, they should log the error and if applicable, return a default value (null, empty collection).
If you really do not expect the default branch to ever be use, throw a RuntimeException when it is.
An empty method may be confusing. Add a nested comment explaining why this method is empty, throw an UnsupportedOperationException or complete the implementation.