text: """
  When there are two or more viewletmanagers available in the module,
  a viewlet will not auto-associate but instead raise an error.
  
    >>> grok.testing.grok(__name__)
    Traceback (most recent call last):
      ...
    martian.error.GrokError: Multiple possible viewletmanagers for <class 'grok.tests.viewlet.viewlet_ambiguous_manager.Viewlet'>, please use the 'viewletmanager' directive.
  """  # noqa: E501
  
  import grok
  from zope.interface import Interface
  
  
  class ViewletManager(grok.ViewletManager):
      grok.name('foo')
      grok.context(Interface)
  
  
  class ViewletManager2(grok.ViewletManager):
      grok.name('bar')
      grok.context(Interface)
  
  
  class Viewlet(grok.Viewlet):
      grok.context(Interface)
  
      def render(self):
          return "Render method"
  