The URL of the discovery document containing the resource's
JSON schema. For example: "https://www.googleapis.com/discov
ery/v1/apis/compute/v1/rest". It will be left unspecified
for resources without a discovery-based API, such as Cloud
Bigtable.
The REST URL for accessing the resource. An HTTP GET operation
using this URL returns the resource itself. Example:
https://cloudresourcemanager.googleapis.com/v1/projects/my-
project-123. It will be left unspecified for resources
without a REST API.
The content of the resource, in which some sensitive fields
are scrubbed away and may not be present.