OLE2 classes and their dependencies are usually harder to reengineer/debug than their OOXML counterparts. For this purpose I've added the GenericRecord interface and a sample Writer GenericRecordJsonWriter. Currently this is provided for HSLF/DDF/WMF/EMF/EMF+ Although this is mainly provided for OLE2 based classes, this can be of course extended to OOXML.
Applied via r1866808 Left open for further OLE2 modules
Replace EscherProperty.getAttributeMap by GenericRecord interface via r1868352
... and r1868353 to provide XmlWriter for GenericRecords
with r1868952 the json writer actually generates valid json with the names in quotes. Furthermore I've added the feature to subclass the writer classes and omit certain properties, which can be displayed/processed otherwise
Add traversing and debugging interface to HSSF via r1876433 This makes toString() implementations obsolete. This also contains preparation for #64036 to (maybe) change the record factory interface of HSSF. Remove duplicated record SeriesToChartGroupRecord, which is a duplicate of SeriesChartGroupIndexRecord.
a few more HSSF / Old Excel classes via r1876732