generator property
What produced this bundle, e.g. tom_ast_generator 0.1.6.
null for a bundle written before AstBundleFormat.keyGenerator existed,
or by a producer that does not set it. See that constant for why it is
recorded. Carried through every serialization format this class offers —
JSON, gzip bytes and the ZIP manifest — because a bundle is diagnosed in
whichever form it arrived in.
Implementation
final String? generator;