Represents a key in a Service Account.
When a key response is received, the content is unpacked and the related attributes are updated.
key_id (str) – Unique key ID.
secret (str, None) – If the Key object was constructed from a newly created key, i.e. from calling the create_key() method, this attributes contains the key secret. This is displayed once, and is otherwise None.
create_time (datetime) – Timestamp of when the key was created.