Description of problem:
Execution of Test() method on Connection object fails with invalid_grant error
visible in the engine's logs:
2020-10-20 15:51:42,295+02 ERROR [org.ovirt.engine.core.sso.utils.SsoUtils] (default task-34) [1ed6edb1] OAuthException invalid_grant: The provided authorization grant for the auth code has expired.
As the result each time new authentication request is sent.
Steps to Reproduce:
1. Setup ovirt-engine
2. Build and run code according to instructions: 
The reason ovirt engine complains with the error desribed above is the fact that HTTP OPTIONS call does not contain proper token in 'Authorization' header - the value seems to be truncated to 'Authorization: Bearer'
I will test the same from Python SDK to see if the problem is in GO or in engine code
I didn't manage to reproduce
Please look at  which runs with no problems on my side (just replace all parameters enclosed with "<>" with yours
1) Did you have "https://" in your URL and it ends with "ovirt-engine/api" as in the example
2) Do you use the format "user@domain" in user field
3) Do you have the correct password ?
I have just realized that I did not add one important instruction.
Ovirt engine must be deployed from RPM (with httpd). Tested against various 4.4.2 variants.
ad1) ack to both parts
ad2) yes - in my case admin@internal
ad3) yes (I shared it privately)
When this client is run it will not end with failure - only error log statement in engine.log is issued (the from the bz description).
I got input from Artur Socha that this is only happening for engines deployed from RPM (with httpd etc)
Looking at the Go Test code and comparing it to java/python SDK connection validation it seems that we don't need all this complexity
It is enough to call the system service Get() method and see that it is not throwing an error
I will push a patch that align Go SDK connection testing with java/python SDK connection testing logic
solved in commit 92c1875a918b8e2f4aaf0d6110be9422dfc1ce10