code: def downgrade():
      pass
  
file_path: superset/superset/migrations/versions/2020-12-23_11-34_c878781977c6_alert_reports_shared_uniqueness.py
imports: import sqlalchemy
  from alembic import op
  from sqlalchemy.dialects.mysql.base import MySQLDialect
  from sqlalchemy.dialects.postgresql.base import PGDialect
  from sqlalchemy.dialects.sqlite.base import SQLiteDialect
  from sqlalchemy.engine.reflection import Inspector
  from superset.utils.core import generic_find_uq_constraint_name
label_desc: Use image node_id 2 for calling a global function with example usage: downgrade() without return types