mergeInto, mergeFrom *workflowpb.WorkflowExecutionOptions,
updateMask *fieldmaskpb.FieldMask,
_, err := fieldmaskpb.New(mergeInto, updateMask.GetPaths()...)
if err != nil { // errors if any paths are not valid for the struct we are merging into
return nil, OptionsToReapply{}, err
}