syntax_data: {"ast_node_type":"other","tokens":[{"end":46,"kind":"keyword","start":0,"text":".flat_map(|principal_def_id|"}]}
source_snippet:                 .flat_map(|principal_def_id| {
context_before:                 .into_iter()
context_after:                     // NOTE: This should agree with `needed_associated_types` in