TFE_Op* matmul = MatMulOp(ctx, m1, m2);
  TFE_OpSetDevice(matmul, "/job:localhost/replica:0/task:0/device:CPU:0",
                  status);
  ASSERT_EQ(TF_OK, TF_GetCode(status)) << TF_Message(status);
  TFE_Op* matmul2 = MatMulOp(ctx, m1, m1);
  TFE_OpSetDevice(matmul2, "/job:localhost/replica:0/task:0/device:CPU:0",
                  status);
  ASSERT_EQ(TF_OK, TF_GetCode(status)) << TF_Message(status);

        const auto& v = a_edges.insert({iter->second, arg.name()});
        ASSERT_TRUE(v.second) << "Duplicate edge " << iter->second << " -> "
                              << arg.name() << ". fdef: " << fdef.DebugString();
      } else {
        const auto& v = a_edges.insert({arg.name(), arg.name()});
        ASSERT_TRUE(v.second) << "Duplicate edge " << arg.name() << " -> "

  /// this method must take ownership of the returned pointer.
  ///
  /// The implementation should clean up paths, including but not limited to,
  /// removing duplicate `/`s, and resolving `..` and `.`.
  ///
  /// Plugins must not return `nullptr`. Returning empty strings is allowed.
  ///
  /// The allocation and freeing of memory must happen via the functions sent to

// Counts the number of elements in the device list.
TF_CAPI_EXPORT extern int TF_DeviceListCount(const TF_DeviceList* list);

// Retrieves the full name of the device (e.g. /job:worker/replica:0/...)
// The return value will be a pointer to a null terminated string. The caller
// must not modify or delete the string. It will be deallocated upon a call to
// TF_DeleteDeviceList.
//