code: func (m MultiRESTMapper) ResourceSingularizer(resource string) (singular string, err error) {
  	for _, t := range m {
  		singular, err = t.ResourceSingularizer(resource)
  		if err == nil {
  			return
  		}
  	}
  	return
  }
docs: // ResourceSingularizer converts a REST resource name from plural to singular (e.g., from pods to pod)
  // This implementation supports multiple REST schemas and return the first match.