code: def downgrade():
      pass
  
file_path: superset/superset/migrations/versions/2018-08-01_11-47_7fcdcde0761c_.py
imports: import json
  import re
  import sqlalchemy
  from alembic import op
  from sqlalchemy.ext.declarative import declarative_base
  from superset import db
label_desc: Use image node_id 3 for calling a global function with example usage: downgrade() without return types