Registers a new environment key with the configuration. Keys and values must also be declared at the type-level by extending the WellknownEnvKeys interface.
WellknownEnvKeys
Throws an exception if the key was already registered.
the env key
the value or a function returning the value (for lazy evaluation).
Optional
registration flags
Registers a new environment key with the configuration. Keys and values must also be declared at the type-level by extending the
WellknownEnvKeysinterface.Throws an exception if the key was already registered.