code: def configure_gs_datastore(existing_env):
      env = {}
      # Set Google Cloud Storage as default datastore.
      env["METAFLOW_DEFAULT_DATASTORE"] = "gs"
      # Set Google Cloud Storage folder for datastore.
      env["METAFLOW_DATASTORE_SYSROOT_GS"] = click.prompt(
          cyan("[METAFLOW_DATASTORE_SYSROOT_GS]")
          + " Google Cloud Storage folder for Metaflow artifact storage "
          + "(Format: gs://<bucket>/<prefix>)",
          default=existing_env.get("METAFLOW_DATASTORE_SYSROOT_GS"),
          show_default=True,
      )
      return env
  
imports: import json
  import os
  import sys
  from os.path import expanduser
  from metaflow.util import to_unicode
  from metaflow._vendor import click
  from metaflow.util import to_unicode
  from .util import echo_always, makedirs
label_desc: Use image node_id 18 for calling a global function with example usage: configure_gs_datastore(existing_env) and returns: env