olefile is a Python package to parse, read and write Microsoft OLE2 files (also called Structured Storage, Compound File Binary Format or Compound Document File Format), such as Microsoft Office 97-2003 documents, vbaProject.bin in MS Office 2007+ files, Image Composer and FlashPix files, Outlook messages, StickyNotes, several Microscopy file formats, McAfee antivirus quarantine files, etc.
header_clsid is a string, we should also have the raw data as bytes. (mostly to be able to modify it, when writing the header is implemented)