code: def upgrade():
      with op.batch_alter_table("tables") as batch_op:
          batch_op.alter_column(
              "fetch_values_predicate",
              existing_type=sa.String(length=1000),
              type_=sa.Text(),
              existing_nullable=True,
          )
  
file_path: superset/superset/migrations/versions/2021-08-09_17-32_07071313dd52_change_fetch_values_predicate_to_text.py
imports: import logging
  import sqlalchemy
  from alembic import op
  from sqlalchemy import func
  from superset import db
  from superset.connectors.sqla.models import SqlaTable
label_desc: Use image node_id 1 for calling a global function with example usage: upgrade() without return types