@abc.abstractmethod<EOL><INDENT>def can_delete_compositions(self):<DEDENT>
return<EOL>
Tests if this user can delete ``Compositions``.

        A return of true does not guarantee successful authorization. A
        return of false indicates that it is known deleting a
        ``Composition`` will result in a ``PermissionDenied``. This is
        intended as a hint to an application that may not wish to offer
        delete operations to unauthorized users.

        :return: ``false`` if ``Composition`` deletion is not authorized, ``true`` otherwise
        :rtype: ``boolean``


        *compliance: mandatory -- This method must be implemented.*