Launch the game.

def start(self, version=None, want_rgb=True, **kwargs):
    """Launch the game."""
    del want_rgb  # Unused
    if not os.path.isdir(self.data_dir):
      raise sc_process.SC2LaunchError(
          "Expected to find StarCraft II installed at '%s'. If it's not "
          "installed, do that and run it once so auto-detection works. If "
          "auto-detection failed repeatedly, then set the SC2PATH environment "
          "variable with the correct location." % self.data_dir)

    version = version or FLAGS.sc2_version
    if isinstance(version, lib.Version) and not version.data_version:
      # This is for old replays that don't have the embedded data_version.
      version = self._get_version(version.game_version)
    elif isinstance(version, six.string_types):
      version = self._get_version(version)
    elif not version:
      version = self._get_version("latest")
    if version.build_version < lib.VERSIONS["3.16.1"].build_version:
      raise sc_process.SC2LaunchError(
          "SC2 Binaries older than 3.16.1 don't support the api.")
    if FLAGS.sc2_dev_build:
      version = version._replace(build_version=0)
    exec_path = os.path.join(
        self.data_dir, "Versions/Base%05d" % version.build_version,
        self._exec_name)

    if not os.path.exists(exec_path):
      raise sc_process.SC2LaunchError("No SC2 binary found at: %s" % exec_path)

    return sc_process.StarcraftProcess(
        self, exec_path=exec_path, version=version, **kwargs)