code: def upgrade():
      op.add_column(
          "task_instance",
          sa.Column("operator", sa.String(length=1000), nullable=True),
      )
      op.add_column(
          "task_instance",
          sa.Column("queued_dttm", sa.DateTime(), nullable=True),
      )
  
imports: from __future__ import annotations
  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