code: def upgrade():
      """Apply Add external executor ID to TI"""
      with op.batch_alter_table(
          "task_instance", schema=None
      ) as batch_op:
          batch_op.add_column(
              sa.Column(
                  "external_executor_id",
                  sa.String(length=250),
                  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