Module Odoc_model__Root
A root can be seen as a unique representative of a odoc file.
Roots are used by doc-ock (at the root of every resolved path/identifier/reference) and present at the beginning of every .odoc file.
module Package : sig ... endmodule Odoc_file : sig ... endtype t={package : Package.t;file : Odoc_file.t;digest : Stdlib.Digest.t;}
module Hash_table : Stdlib.Hashtbl.S with type Hash_table.key = t