def construct_runtime_cache_folder(runtime_cache_prefix, ios_version):
  """Composes runtime cache folder from it's prefix and ios_version.

  Note: Please keep the pattern consistent between what's being passed into
  runner script in gn(build/config/ios/ios_test_runner_wrapper.gni), and what's
  being configured for swarming cache in test configs (testing/buildbot/*).
  """
  return runtime_cache_prefix + ios_version