private void readDirectlyAndEnsureMatch(LogSegment segment, long offsetToStartRead, byte[] original)
      throws IOException {
    if (Utils.isLinux()) {
      byte[] byteArray = new byte[original.length];
      segment.readIntoDirectly(byteArray, offsetToStartRead, original.length);
      assertArrayEquals("Data read does not match data written", original, byteArray);
    }
  }
Reads data(direct IO) starting from {@code offsetToStartRead} of {@code segment} and matches it with {@code original}.
@param segment the {@link LogSegment} to read from.
@param offsetToStartRead the offset in {@code segment} to start reading from.
@param original the byte array to compare against.
@throws IOException
ambry-store/src/test/java/com/github/ambry/store/LogSegmentTest.java