code: public static int cudnnGetConvolutionBackwardFilterWorkspaceSize(
          cudnnHandle handle, 
          cudnnTensorDescriptor xDesc, 
          cudnnTensorDescriptor dyDesc, 
          cudnnConvolutionDescriptor convDesc, 
          cudnnFilterDescriptor gradDesc, 
          int algo, 
          long[] sizeInBytes)
      {
          return checkResult(cudnnGetConvolutionBackwardFilterWorkspaceSizeNative(handle, xDesc, dyDesc, convDesc, gradDesc, algo, sizeInBytes));
      }
docs: Helper function to return the minimum size of the workspace to be passed to the convolution given an algo