syntax_data: {"ast_node_type":"import","tokens":[{"end":78,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:     // because we are not able to make any progress at all. This is to prevent
context_before:     // However, if `arg` IS an unresolved inference variable, returns `None`,
context_after:     // cycles where we say "?0 is WF if ?0 is WF".