Copies properties defined in sourceToTargetMapping from source to target.
Copies properties defined in sourceToTargetMapping from source to target. If source config keys don't exist, the method returns a Failure. If the specified target keys already exist, the method returns a Failure.
config to copy properties from. Won't be mutated by this method.
config to copy properties into. This method mutates the target configuration.
mapping from source config keys to target config keys
target configuration, wrapped in Try