code: function processFirebaseBindings (instance) {
    var refs = instance.$firebaseRefs
    if (refs) {
      return Object.keys(refs).map(key => {
        return {
          type: 'firebase bindings',
          key,
          value: instance[key]
        }
      })
    } else {
      return []
    }
  }
docs: Process Firebase bindings.
  
  @param {Vue} instance
  @return {Array}