I got Snappy, Brotli, Zstd and LZ4 working in pure M by tricking Parquet.Document into being a decompressor

Parquet.Document as a codec oracle for Snappy, Brotli, Std **TL;DR:** Binary.Decompress only does GZip and Deflate. Ask for Snappy, Brotli, Zstandard or LZ4 and it throws, even though the enum declares all four. But the engine has those codecs, Parquet.Document uses them on every compressed Parquet read. So wrap your blob in a tiny Parquet file and let the reader do the work. Pure M, no connector. The trick A Parquet data page is compressed as a single unit and the codec is named in the file metadata. So the schema is one REQUIRED FIXED_LEN_BYTE_ARRAY(N) column, one row, PLAIN encoding. That i