How to use the ember-metal/utils.guidFor function in ember-metal

function mixinProperties(mixinsMeta, mixin) {
  var guid;

  if (mixin instanceof Mixin) {
    guid = guidFor(mixin);
    if (mixinsMeta[guid]) { return CONTINUE; }
    mixinsMeta[guid] = mixin;
    return mixin.properties;
  } else {
    return mixin; // apply anonymous mixin properties
  }
}

return tag.get('name').toLowerCase();
                });

                // find existing tag or create new
                if (availableTagNames.contains(tagName.toLowerCase())) {
                    tagToAdd = availableTags.find((tag) => {
                        return tag.get('name').toLowerCase() === tagName.toLowerCase();
                    });
                } else {
                    tagToAdd = this.get('store').createRecord('tag', {
                        name: tagName
                    });

                    // we need to set a UUID so that selectize has a unique value
                    // it will be ignored when sent to the server
                    tagToAdd.set('uuid', guidFor(tagToAdd));
                }

                // push tag onto post relationship
                if (tagToAdd) {
                    this.get('model.tags').insertAt(index, tagToAdd);
                }
            });
        },

var isLast = idx === len-1;
    var last, removed;


    if (idx>=0 && idx

function _keys(ret, mixin, seen) {
  if (seen[guidFor(mixin)]) { return; }
  seen[guidFor(mixin)] = true;

  if (mixin.properties) {
    var props = mixin.properties;
    for (var key in props) {
      if (props.hasOwnProperty(key)) { ret[key] = true; }
    }
  } else if (mixin.mixins) {
    a_forEach.call(mixin.mixins, (x) => {
      _keys(ret, x, seen);
    });
  }
}

function identity(item) {
  let key;
  let type = typeof item;

  if (type === 'string' || type === 'number') {
    key = item;
  } else {
    key = guidFor(item);
  }

  return key;
}
export default function decodeEachKey(item, keyPath, index) {

MixinPrototype.detect = function(obj) {
  if (!obj) { return false; }
  if (obj instanceof Mixin) { return _detect(obj, this, {}); }
  var m = obj['__ember_meta__'];
  var mixins = m && m.mixins;
  if (mixins) {
    return !!mixins[guidFor(this)];
  }
  return false;
};

function removeObserverForContentKey(content, keyName, proxy, idx, loc) {
  var objects = proxy._objects;
  if (!objects) objects = proxy._objects = {};
  var indicies, guid;

  while(--loc>=idx) {
    var item = content.objectAt(loc);
    if (item) {
      removeBeforeObserver(item, keyName, proxy, 'contentKeyWillChange');
      removeObserver(item, keyName, proxy, 'contentKeyDidChange');

      guid = guidFor(item);
      indicies = objects[guid];
      indicies[indexOf.call(indicies, loc)] = null;
    }
  }
}