presto-main/src/main/java/io/prestosql/execution/resourcegroups/LegacyResourceGroupConfigurationManager.java/LegacyResourceGroupConfigurationManager/parentGroupContext
class LegacyResourceGroupConfigurationManager:    @Override
    public SelectionContext<VoidContext> parentGroupContext(SelectionContext<VoidContext> context)
    {
        return new SelectionContext<>(
                context.getResourceGroupId().getParent().orElseThrow(() -> new IllegalArgumentException("Group has no parent group: " + context.getResourceGroupId())),
                VoidContext.NONE);
    }