KeyDistribution keyDistri = reader.getKeyDistribution(numSplits * 10);
Assert.assertEquals(totalBytes, keyDistri.length());
reader.close();
BytesWritable[] keys = null;
if (keyDistri.size() >= numSplits) {
keyDistri.resize(numSplits);
Assert.assertEquals(totalBytes, keyDistri.length());
RawComparable[] rawComparables = keyDistri.getKeys();
keys = new BytesWritable[rawComparables.length];
for (int i = 0; i < keys.length; ++i) {
keys[i] = new BytesWritable();