old_contents: """Example Let's Encrypt plugins.
  
  For full examples, see `letsencrypt.plugins`.
  
  """
  import zope.interface
  
  from letsencrypt import interfaces
  from letsencrypt.plugins import common
  
  
  class Authenticator(common.Plugin):
      """Example Authenticator."""
      zope.interface.implements(interfaces.IAuthenticator)
      zope.interface.classProvides(interfaces.IPluginFactory)
  
      description = "Example Authenticator plugin"
  
      # Implement all methods from IAuthenticator, remembering to add
      # "self" as first argument, e.g. def prepare(self)...
  
  
  class Installer(common.Plugins):
      """Example Installer."""
      zope.interface.implements(interfaces.IInstaller)
      zope.interface.classProvides(interfaces.IPluginFactory)
  
      description = "Example Installer plugin"
  
      # Implement all methods from IInstaller, remembering to add
      # "self" as first argument, e.g. def get_all_names(self)...
  
new_contents: """Example Let's Encrypt plugins.
  
  For full examples, see `letsencrypt.plugins`.
  
  """
  import zope.interface
  
  from letsencrypt import interfaces
  from letsencrypt.plugins import common
  
  
  class Authenticator(common.Plugin):
      """Example Authenticator."""
      zope.interface.implements(interfaces.IAuthenticator)
      zope.interface.classProvides(interfaces.IPluginFactory)
  
      description = "Example Authenticator plugin"
  
      # Implement all methods from IAuthenticator, remembering to add
      # "self" as first argument, e.g. def prepare(self)...
  
  
  class Installer(common.Plugin):
      """Example Installer."""
      zope.interface.implements(interfaces.IInstaller)
      zope.interface.classProvides(interfaces.IPluginFactory)
  
      description = "Example Installer plugin"
  
      # Implement all methods from IInstaller, remembering to add
      # "self" as first argument, e.g. def get_all_names(self)...
  
subject: Fix typo in examples