You can search for identifiers within the package.
in-package search v0.2.0
server-reason-react.belt
MutableSet.S
type ('value, 'id) t
val t : cmp:('value, 'id) cmp -> data:'value N.t -> ('value, 'id) t
val cmp : ('value, 'id) t -> ('value, 'id) cmp
val dataSet : ('value, 'id) t -> 'value N.t -> unit
val data : ('value, 'id) t -> 'value N.t