old_contents: """Mock module for Sphinx autodoc."""
  
  
  class FFI(object):
      def cdef(self, _):
          pass
  
      def dlopen(self, _):
          return self
  
      NULL = NotImplemented
  
      JackTransportStopped = 0
      JackTransportRolling = 1
      JackTransportStarting = 3
      JackTransportNetStarting = 4
  
new_contents: """Mock module for Sphinx autodoc."""
  
  
  class FFI(object):
      def cdef(self, _, packed=NotImplemented):
          pass
  
      def dlopen(self, _):
          return self
  
      NULL = NotImplemented
  
      JackTransportStopped = 0
      JackTransportRolling = 1
      JackTransportStarting = 3
      JackTransportNetStarting = 4
  
subject: Add kwarg "packed" to fake_cffi