Map<PartitionId, List<ByteBuffer>> getMissingBuffers(Map<PartitionId, List<ByteBuffer>> other) {
    Map<PartitionId, List<ByteBuffer>> missingBuffers = new HashMap<>();
    for (Map.Entry<PartitionId, List<ByteBuffer>> entry : buffersByPartition.entrySet()) {
      PartitionId partitionId = entry.getKey();
      for (ByteBuffer buf : entry.getValue()) {
        boolean found = false;
        for (ByteBuffer bufActual : other.get(partitionId)) {
          if (Arrays.equals(buf.array(), bufActual.array())) {
            found = true;
            break;
          }
        }
        if (!found) {
          missingBuffers.computeIfAbsent(partitionId, partitionId1 -> new ArrayList<>()).add(buf);
        }
      }
    }
    return missingBuffers;
  }
Gets the buffers that are present in this host but missing in {@code other}.
@param other the list of {@link ByteBuffer} to check against.
@return the buffers that are present in this host but missing in {@code other}.
ambry-replication/src/test/java/com/github/ambry/replication/MockHost.java