docs: def validate_configuration(config):
      # type: (Config) -> None
      """Validate app configuration.
  
      The purpose of this method is to provide a fail fast mechanism
      for anything we know is going to fail deployment.
      We can detect common error cases and provide the user with helpful
      error messages.
  
      """
      routes = config.chalice_app.routes
      validate_routes(routes)
      validate_route_content_types(routes, config.chalice_app.api.binary_types)
      _validate_manage_iam_role(config)
      validate_python_version(config)
      validate_unique_function_names(config)
      validate_feature_flags(config.chalice_app)