syntax_data: {"ast_node_type":"other","tokens":[{"end":68,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:             // different values for `-Cmetadata=ab -Cmetadata=c` and
context_before:             // Also incorporate the length of a metadata string, so that we generate
context_after:             // `-Cmetadata=a -Cmetadata=bc`