func (c *threadSafeMap) AddIndexers(newIndexers Indexers) error {
	c.lock.Lock()
	defer c.lock.Unlock()

	if len(c.items) > 0 {
		return fmt.Errorf("cannot add indexers to running index")
	}

	oldKeys := sets.StringKeySet(c.indexers)
	newKeys := sets.StringKeySet(newIndexers)

	if oldKeys.HasAny(newKeys.List()...) {
		return fmt.Errorf("indexer conflict: %v", oldKeys.Intersection(newKeys))
	}

	for k, v := range newIndexers {
		c.indexers[k] = v
	}
	return nil
}
func newNavigationSteps(path string) (*navigationSteps, error) {
	steps := []navigationStep{}
	individualParts := strings.Split(path, ".")

	currType := reflect.TypeOf(clientcmdapi.Config{})
	currPartIndex := 0
	for currPartIndex < len(individualParts) {
		switch currType.Kind() {
		case reflect.Map:
			// if we're in a map, we need to locate a name.  That name may contain dots, so we need to know what tokens are legal for the map's value type
			// for example, we could have a set request like: `set clusters.10.10.12.56.insecure-skip-tls-verify true`.  We enter this case with
			// steps representing 10, 10, 12, 56, insecure-skip-tls-verify.  The name is "10.10.12.56", so we want to collect all those parts together and
			// store them as a single step.  In order to do that, we need to determine what set of tokens is a legal step AFTER the name of the map key
			// This set of reflective code pulls the type of the map values, uses that type to look up the set of legal tags.  Those legal tags are used to
			// walk the list of remaining parts until we find a match to a legal tag or the end of the string.  That name is used to burn all the used parts.
			mapValueType := currType.Elem().Elem()
			mapValueOptions, err := getPotentialTypeValues(mapValueType)
			if err != nil {
				return nil, err
			}
			nextPart := findNameStep(individualParts[currPartIndex:], sets.StringKeySet(mapValueOptions))

			steps = append(steps, navigationStep{nextPart, mapValueType})
			currPartIndex += len(strings.Split(nextPart, "."))
			currType = mapValueType

		case reflect.Struct:
			nextPart := individualParts[currPartIndex]

			options, err := getPotentialTypeValues(currType)
			if err != nil {
				return nil, err
			}
			fieldType, exists := options[nextPart]
			if !exists {
				return nil, fmt.Errorf("unable to parse %v after %v at %v", path, steps, currType)
			}

			steps = append(steps, navigationStep{nextPart, fieldType})
			currPartIndex += len(strings.Split(nextPart, "."))
			currType = fieldType
		}
	}

	return &navigationSteps{steps, 0}, nil
}