Validates that a grant has not expired.
The grant file to check. Must include expiry timestamp if time-limited.
Optional
Optional time override for testing. Unix timestamp in seconds. Defaults to current time.
If grant has expired. Request a new grant from the data owner.
validateGrantExpiry(grantFile);// Throws if current time > grantFile.expires Copy
validateGrantExpiry(grantFile);// Throws if current time > grantFile.expires
Validates that a grant has not expired.