code: def upgrade():
      with op.batch_alter_table("clusters") as batch_op:
          batch_op.drop_column("coordinator_host")
          batch_op.drop_column("coordinator_endpoint")
          batch_op.drop_column("coordinator_port")
  
imports: import sqlalchemy
  from alembic import op
label_desc: Use image node_id 1 for calling a global function with example usage: upgrade() without return types