{"ast_node_type":"function","tokens":[{"end":71,"kind":"keyword","start":0,"text":"fn"}]}
    fn project_constant_index(&self, bx: &mut Bx, offset: u64) -> Self;
    fn project_field(&self, bx: &mut Bx, field: FieldIdx) -> Self;
    fn downcast(&self, bx: &mut Bx, variant: VariantIdx) -> Self;