{"ast_node_type":"other","tokens":[{"end":64,"kind":"keyword","start":0,"text":"mapped_consts:"}]}
    mapped_consts: IndexMap<I::PlaceholderConst, I::BoundConst>,
    mapped_types: IndexMap<I::PlaceholderTy, I::BoundTy>,
    // The current depth relative to *this* folding, *not* the entire normalization. In other words,