How to use

setValueCount

method

in

org.apache.arrow.vector.complex.UnionVector

@Override
public void splitAndTransfer(int startIndex, int length) {
 to.clear();
 internalStructVectorTransferPair.splitAndTransfer(startIndex, length);
 final int startPoint = startIndex * TYPE_WIDTH;
 final int sliceLength = length * TYPE_WIDTH;
 to.typeBuffer = typeBuffer.slice(startPoint, sliceLength).transferOwnership(to.allocator).buffer;
 to.setValueCount(length);
}

unionWriter.writeVarChar(0, varCharVal.length, tempBuf);
colUnionV.setValueCount(5);