# def upgrade():
#     op.create_check_constraint(
#         'lossy_xor_lossless',
#         table_name='qualities',
#         schema='metadata',
#         condition='(settings_lossy_id IS NULL) <> '\
#                 '(settings_lossless_id IS NULL)'
#     )
#
#
# def downgrade():
#     op.drop_constraint('lossy_xor_lossless')

# def upgrade():
#     op.create_check_constraint(
#         'lossy_xor_lossless',
#         table_name='qualities',
#         schema='metadata',
#         condition='(settings_lossy_id IS NULL) <> '\
#                 '(settings_lossless_id IS NULL)'
#     )
#
#
# def downgrade():
#     op.drop_constraint('lossy_xor_lossless')

# def upgrade(): #     op.create_check_constraint( #         'lossy_xor_lossless', #         table_name='qualities', #         schema='metadata', #         condition='(settings_lossy_id IS NULL) <> '\ #                 '(settings_lossless_id IS NULL)' #     ) # # # def downgrade(): #     op.drop_constraint('lossy_xor_lossless')