old_contents: revision = '346102165a4'
  down_revision = '5ae64c689b2'
  
  from alembic import op
  import sqlalchemy as sa
  
  
  def upgrade():
      op.create_unique_constraint('meta_unique_object_id_key',
                                  'meta', ['object_id', 'key'])
      op.create_index('meta_object_id_index', 'meta', ['object_id'])
  
  
  def downgrade():
      op.drop_index('meta_object_id_index')
      op.drop_constraint('meta_unique_objectid_key', 'meta')
  
new_contents: revision = '346102165a4'
  down_revision = '5ae64c689b2'
  
  from alembic import op
  import sqlalchemy as sa
  
  
  def upgrade():
      op.create_unique_constraint('meta_unique_object_id_key',
                                  'meta', ['object_id', 'key'])
      op.create_index('meta_object_id_index', 'meta', ['object_id'])
  
  
  def downgrade():
      op.drop_index('meta_object_id_index')
      op.drop_constraint('meta_unique_object_id_key', 'meta')
  
subject: fix the downgrade script