code: def upgrade():
      """
      Enlarge the maximum param value length to 500.
      """
      with op.batch_alter_table("params") as batch_op:
          batch_op.alter_column(
              "value",
              existing_type=sa.String(250),
              type_=sa.String(500),
              existing_nullable=False,
              nullable=False,
          )
  
imports: from alembic import op
  import sqlalchemy
label_desc: Use image node_id 1 for calling a global function with example usage: upgrade() without return types