code: def snippets(session):
      
  
      # Sanity check: Only run snippets tests if the environment variable is set.
      if not os.environ.get("GOOGLE_APPLICATION_CREDENTIALS", ""):
          session.skip("Credentials must be set via environment variable.")
  
      # Install all test dependencies, then install local packages in place.
      session.install("mock", "pytest")
      for local_dep in LOCAL_DEPS:
          session.install("-e", local_dep)
      session.install("-e", os.path.join("..", "storage"))
      session.install("-e", os.path.join("..", "test_utils"))
      session.install("-e", ".[all]")
  
      # Run py.test against the snippets tests.
      session.run("py.test", os.path.join("docs", "snippets.py"), *session.posargs)
      session.run("py.test", "samples", *session.posargs)
docs: Run the snippets test suite.