code: def _pytorch_hidden_to_coreml(self, x):
      # Split of Direction axis
      f, b = torch.split(x, [1] * x.shape[0], dim=0)
      # Concat on Hidden Size axis
      x = torch.cat((f, b), dim=2)
      # NOTE:
      # We are ommiting a squeeze because the conversion
      # function for the mil op lstm unsqueezes the num_layers
      # dimension
      return x
  
imports: import sys
  from coremltools.converters.mil import testing_reqs
  from coremltools.converters.mil.testing_reqs import *
  from .testing_utils import *
label_desc: Use image node_id 1 for calling the TestLSTM obj's underlying member method code with example usage: obj._pytorch_hidden_to_coreml(x) and returns: x