code: function prepareTypesArg (types) {
    if (Array.isArray(types)) {
      return types
    }
    if (types instanceof String) {
      types += ''
    }
    if (typeof types === 'string') {
      return types.trim().split(' ').filter(Boolean)
    }
    return [types]
  }
docs: ********** UTILITY FUNCTIONS ********** //