  explicit Conv3DCustomBackpropFilterOp(OpKernelConstruction* context)
      : OpKernel(context),
        data_format_(FORMAT_NHWC),
        takes_shape_(type_string().find("V2") != std::string::npos) {
    // data_format is only available in V2.
    if (takes_shape_) {
      string data_format;
      OP_REQUIRES_OK(context, context->GetAttr("data_format", &data_format));
      OP_REQUIRES(context, FormatFromString(data_format, &data_format_),
                  errors::InvalidArgument("Invalid data format"));
      OP_REQUIRES(
          context, data_format_ == FORMAT_NHWC,
          errors::InvalidArgument(
              "Conv3DBackpropFilterOpV2 only supports NDHWC on the CPU."));
    }

    OP_REQUIRES_OK(context, context->GetAttr("dilations", &dilation_));
    OP_REQUIRES(context, dilation_.size() == 5,
                errors::InvalidArgument("Dilation rates field must "
                                        "specify 5 dimensions"));
    OP_REQUIRES(context,
                (GetTensorDim(dilation_, data_format_, 'C') == 1 &&
                 GetTensorDim(dilation_, data_format_, 'N') == 1),
                errors::InvalidArgument(
                    "Current implementation does not yet support "
                    "dilation rates in the batch and depth dimensions."));

    // TODO(yangzihao): Add CPU version of dilated conv 3D.
    OP_REQUIRES(context,
                (GetTensorDim(dilation_, data_format_, '0') == 1 &&
                 GetTensorDim(dilation_, data_format_, '1') == 1 &&
                 GetTensorDim(dilation_, data_format_, '2') == 1),
                errors::InvalidArgument(
                    "Current CPU implementation does not yet support "
                    "dilation rates larger than 1."));

    OP_REQUIRES_OK(context, context->GetAttr("strides", &stride_));
    OP_REQUIRES(context, stride_.size() == 5,
                errors::InvalidArgument("Sliding window strides field must "
                                        "specify 5 dimensions"));
    OP_REQUIRES(
        context,
        (GetTensorDim(stride_, data_format_, 'C') == 1 &&
         GetTensorDim(stride_, data_format_, 'N') == 1),
        errors::InvalidArgument("Current implementation does not yet support "
                                "strides in the batch and depth dimensions."));
    OP_REQUIRES_OK(context, context->GetAttr("padding", &padding_));
  }
  explicit Conv3DCustomBackpropFilterOp(OpKernelConstruction* context)
      : OpKernel(context),
        data_format_(FORMAT_NHWC),
        takes_shape_(type_string().find("V2") != std::string::npos) {
     
    if (takes_shape_) {
      string data_format;
      OP_REQUIRES_OK(context, context->GetAttr("data_format", &data_format));
      OP_REQUIRES(context, FormatFromString(data_format, &data_format_),
                  errors::InvalidArgument("Invalid data format"));
      OP_REQUIRES(
          context, data_format_ == FORMAT_NHWC,
          errors::InvalidArgument(
              "Conv3DBackpropFilterOpV2 only supports NDHWC on the CPU."));
    }

    OP_REQUIRES_OK(context, context->GetAttr("dilations", &dilation_));
    OP_REQUIRES(context, dilation_.size() == 5,
                errors::InvalidArgument("Dilation rates field must "
                                        "specify 5 dimensions"));
    OP_REQUIRES(context,
                (GetTensorDim(dilation_, data_format_, 'C') == 1 &&
                 GetTensorDim(dilation_, data_format_, 'N') == 1),
                errors::InvalidArgument(
                    "Current implementation does not yet support "
                    "dilation rates in the batch and depth dimensions."));

     
    OP_REQUIRES(context,
                (GetTensorDim(dilation_, data_format_, '0') == 1 &&
                 GetTensorDim(dilation_, data_format_, '1') == 1 &&
                 GetTensorDim(dilation_, data_format_, '2') == 1),
                errors::InvalidArgument(
                    "Current CPU implementation does not yet support "
                    "dilation rates larger than 1."));

    OP_REQUIRES_OK(context, context->GetAttr("strides", &stride_));
    OP_REQUIRES(context, stride_.size() == 5,
                errors::InvalidArgument("Sliding window strides field must "
                                        "specify 5 dimensions"));
    OP_REQUIRES(
        context,
        (GetTensorDim(stride_, data_format_, 'C') == 1 &&
         GetTensorDim(stride_, data_format_, 'N') == 1),
        errors::InvalidArgument("Current implementation does not yet support "
                                "strides in the batch and depth dimensions."));
    OP_REQUIRES_OK(context, context->GetAttr("padding", &padding_));
  }