val reserve : Ppxlib__.Import.string ‑> Ppxlib__.Import.unit
reserve "foo"
has two implications:
check_unused
This is here to insure that the rewriter cohabits well with other rewriter or tools (e.g. merlin) which might leave attribute on the AST.
N.B. the "merlin" namespace is reserved by default.
val is_in_reserved_namespaces : Ppxlib__.Import.string ‑> Ppxlib__.Import.bool