code: public static int cusparseXcsr2bsrNnz(
          cusparseHandle handle, 
          int dirA, 
          int m, 
          int n, 
          cusparseMatDescr descrA, 
          Pointer csrSortedRowPtrA, 
          Pointer csrSortedColIndA, 
          int blockDim, 
          cusparseMatDescr descrC, 
          Pointer bsrSortedRowPtrC, 
          Pointer nnzTotalDevHostPtr)
      {
          return checkResult(cusparseXcsr2bsrNnzNative(handle, dirA, m, n, descrA, csrSortedRowPtrA, csrSortedColIndA, blockDim, descrC, bsrSortedRowPtrC, nnzTotalDevHostPtr));
      }
docs: Description: This routine converts a sparse matrix in CSR storage format
  to a sparse matrix in block-CSR storage format.