@utilities.arguments_not_none<EOL><INDENT>def copy_gradebook_column_entries(self, source_gradebook_column_id, target_gradebook_column_id):<DEDENT>
raise errors.Unimplemented()<EOL>
Copies gradebook column entries from one column to another.

        If the target grade column grade system differs from the source,
        the grades in the entries are transformed to the new grade
        system.

        arg:    source_gradebook_column_id (osid.id.Id): the ``Id`` of a
                ``GradebookColumn``
        arg:    target_gradebook_column_id (osid.id.Id): the ``Id`` of a
                ``GradebookColumn``
        raise:  NotFound - ``source_gradebook_column_id
                ortarget_gradebook_column_id`` is not found
        raise:  NullArgument - ``source_gradebook_column_id
                target_gradebook_column_id`` is ``null``
        raise:  OperationFailed - unable to complete request
        raise:  PermissionDenied - authorization failure
        *compliance: mandatory -- This method must be implemented.*