ExceptionHelper is a class useid to rethrow
a specific iFS exception (thrown by the repository) into
a more generalized FileSystem exception (e.g., file not found).
Some prepared statements return multiple results; the execute
method handles these complex statements as well as the simpler
form of statements handled by executeQuery and executeUpdate.
Updates any system attributes appropriate for creating this
object; in this case, invoke a name uniqueness enforcement
method if specified by a Policy.
Update any system attributes appropriate for creating this
object; in this case, set the is_shared attr to true and add
the uniquename attribute to the system list.