class_docstr: Helper methods for Airflow Handler.
class_docstr_tok: ["Helper","methods","for","Airflow","Handler","."]
docstr: Trigger DAG in Airflow.
docstr_tok: ["Trigger","DAG","in","Airflow","."]
code: def create_run(self) -> None:
      """Trigger DAG in Airflow."""
      pipeline_name = self.flags_dict[labels.PIPELINE_NAME]
      runtime_parameter_json = json.dumps(
          self.flags_dict[labels.RUNTIME_PARAMETER]
      )
  
      # Check if pipeline exists.
      self._check_pipeline_existence(pipeline_name)
  
      # Unpause DAG.
      self._subprocess_call(
          ["airflow", "dags", "unpause", pipeline_name]
      )
  
      # Trigger DAG.
      self._subprocess_call(
          [
              "airflow",
              "dags",
              "trigger",
              "--conf",
              runtime_parameter_json,
              pipeline_name,
          ]
      )
  
      click.echo("Run created for pipeline: " + pipeline_name)
  
imports: import json
  import os
  import subprocess
  from typing import Any, Dict, List
  import click
  from tfx.dsl.io import fileio
  from tfx.tools.cli import labels
  from tfx.tools.cli.handler import airflow_dag_runner_patcher
  from tfx.tools.cli.handler import base_handler
  from tfx.utils import io_utils
label_desc: Use image node_id 9 for calling the AirflowHandler obj's underlying member method code with example usage: obj.create_run() without return types