syntax_data: {"ast_node_type":"other","tokens":[{"end":91,"kind":"keyword","start":0,"text":"\"unused-externs-silent\""}]}
source_snippet:                 "unused-externs-silent" => json_unused_externs = JsonUnusedExterns::Silent,
context_before:                 "unused-externs" => json_unused_externs = JsonUnusedExterns::Loud,
context_after:                 "future-incompat" => json_future_incompat = true,