docs: public static String stringFor(int n)
      {
          switch (n)
          {
              case CUDNN_ACTIVATION_SIGMOID: return "CUDNN_ACTIVATION_SIGMOID";
              case CUDNN_ACTIVATION_RELU: return "CUDNN_ACTIVATION_RELU";
              case CUDNN_ACTIVATION_TANH: return "CUDNN_ACTIVATION_TANH";
              case CUDNN_ACTIVATION_CLIPPED_RELU: return "CUDNN_ACTIVATION_CLIPPED_RELU";
              case CUDNN_ACTIVATION_ELU: return "CUDNN_ACTIVATION_ELU";
              case CUDNN_ACTIVATION_IDENTITY: return "CUDNN_ACTIVATION_IDENTITY";
          }
          return "INVALID cudnnActivationMode: "+n;
      }