class_docstr: Base Handler for CLI.
  
  Attributes:
    flags_dict: A dictionary with flags provided in a command.
docstr: Execute DSL file with given patcher applied to the DSL Runner.
code: def execute_dsl(
      self, patcher: dag_runner_patcher.DagRunnerPatcher
  ) -> Dict[str, Any]:
      """Execute DSL file with given patcher applied to the DSL Runner."""
      self._check_pipeline_dsl_path()
      dsl_path = self.flags_dict[labels.PIPELINE_DSL_PATH]
  
      with patcher.patch() as context:
          # Simluate python script execution.
          # - Need to add the script directory as a first entry of sys.path.
          # - Load the script as if we are in __main__ module.
          # - Hide argv given to CLI from the executed script.
          dir_path = os.path.dirname(os.path.realpath(dsl_path))
          sys.path.insert(0, dir_path)
          loader = machinery.SourceFileLoader("__main__", dsl_path)
          old_argv = sys.argv
          sys.argv = [
              dsl_path
          ]  # As if the script is invoked directly with no arg.
          try:
              loader.exec_module(
                  import_util.module_from_spec(
                      import_util.spec_from_loader(loader.name, loader)
                  )
              )
          except (
              SystemExit
          ) as system_exit:  # Swallow normal exit in absl.app.run()
              if system_exit.code != 0 and system_exit.code is not None:
                  raise
          finally:
              sys.argv = old_argv
              sys.path.pop(0)
  
          if not patcher.run_called:
              sys.exit(
                  "Cannot find "
                  + patcher.get_runner_class().__name__
                  + ".run() in "
                  + dsl_path
              )
          return context
  
imports: import abc
  from importlib import machinery
  from importlib import util
  import json
  import os
  import subprocess
  import sys
  from typing import Any, Collection, Dict, List, Optional
  import click
  from tfx.dsl.components.base import base_driver
  from tfx.dsl.io import fileio
  from tfx.tools.cli import labels
  from tfx.tools.cli.handler import dag_runner_patcher
  from tfx.utils import io_utils
label_desc: Use image node_id 13 for calling the BaseHandler obj's underlying member method code with example usage: obj.execute_dsl(patcher) and returns: context