code: def downgrade():
      """Remove map_index from Log."""
      with op.batch_alter_table("log") as batch_op:
          batch_op.drop_column("map_index")
  
imports: from __future__ import annotations
  from alembic import op
  from sqlalchemy import Column, Integer
label_desc: Use image node_id 2 for calling a global function with example usage: downgrade() without return types