return x
  m = torch.jit.script(MyModule())

  # Error! The call `debugger` cannot be saved since it calls into Python
  m.save("m.pt")

Example (using "@torch.jit.ignore(drop=True)" on a method):
  import torch
  import torch.nn as nn

  class MyModule(nn.Module):
      @torch.jit.ignore(drop=True)
      def training_method(self, x):
          import pdb
          pdb.set_trace()

      def forward(self, x):
          if self.training:
              self.training_method(x)
          return x

  m = torch.jit.script(MyModule())

  # This is OK since `training_method` is not saved, the call is replaced
  # with a `raise`.
  m.save("m.pt")
