@Override
  public final Iterator<List<HStoreFile>> iterator() {
    return new Iterator<List<HStoreFile>>() {
      private int count = 0;

      @Override
      public boolean hasNext() {
        return count < MAX_FILE_GEN_ITERS;
      }

      @Override
      public List<HStoreFile> next() {
        count += 1;
        ArrayList<HStoreFile> files = new ArrayList<>(NUM_FILES_GEN);
        for (int i = 0; i < NUM_FILES_GEN; i++) {
          files.add(createMockStoreFile(FILESIZE));
        }
        return files;
      }

      @Override
      public void remove() {

      }
    };
  }
How many mb's mock storefiles should be.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/compactions/ConstantSizeFileListGenerator.java