code: def inner(tensor0: BKTensor, tensor1: BKTensor) -> BKTensor:
      
      N = torch.numel(tensor0[0])
      tensor0_real = tensor0[0].contiguous().view(N)
      tensor0_imag = tensor0[1].contiguous().view(N)
      tensor1_real = tensor1[0].contiguous().view(N)
      tensor1_imag = tensor1[1].contiguous().view(N)
  
      res = (torch.matmul(tensor0_real, tensor1_real)
             + torch.matmul(tensor0_imag, tensor1_imag),
             torch.matmul(tensor0_real, tensor1_imag)
             - torch.matmul(tensor0_imag, tensor1_real))
  
      return _DTYPE(res)
docs: Return the inner product between two tensors