code: def _check_pip_installed():
      
      try:
          subprocess.check_output(
              [sys.executable, "-m", "pip", "--version"], stderr=subprocess.STDOUT
          )
          return True
      except subprocess.CalledProcessError:
          return False
docs: Invoke `pip --version` and make sure it doesn't error.
      Use check_output to capture stdout and stderr
  
      Invokes pip by the same manner that we plan to in _call_pip()
  
      Don't bother trying to reuse _call_pip to do this... Finnicky and not worth
      the effort.