parquet-hadoop/src/main/java/org/apache/parquet/format/converter/ParquetMetadataConverter.java
static FileMetaData filterFileMetaDataByStart(FileMetaData metaData, OffsetMetadataFilter filter) {
    List<RowGroup> rowGroups = metaData.getRow_groups();
    List<RowGroup> newRowGroups = new ArrayList<RowGroup>();
    for (RowGroup rowGroup : rowGroups) {
      long startIndex = getOffset(rowGroup.getColumns().get(0));
      if (filter.contains(startIndex)) {
        newRowGroups.add(rowGroup);
      }
    }
    metaData.setRow_groups(newRowGroups);
    return metaData;
  }
static FileMetaData filterFileMetaDataByStart(FileMetaData metaData, OffsetMetadataFilter filter) {
    List<RowGroup> rowGroups = metaData.getRow_groups();
    List<RowGroup> newRowGroups = new ArrayList<RowGroup>();
    for (RowGroup rowGroup : rowGroups) {
      long startIndex = getOffset(rowGroup.getColumns().get(0));
      if (filter.contains(startIndex)) {
        newRowGroups.add(rowGroup);
      }
    }
    metaData.setRow_groups(newRowGroups);
    return metaData;
  }
Visible for testing