syntax_data: {"ast_node_type":"other","tokens":[{"end":72,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// belongs, but it may not exist if it's a tuple field (`tuple.0`).
context_before:     /// about the field you also need definition of the variant to which the field
context_after:     field_indices: ItemLocalMap<FieldIdx>,