type 'a tA t represents the edge from a child incremental to a parent expert node. A
t is stateful, you cannot use the same t to link one child node to multiple
parents at the same time.
include sig ... endval sexp_of_t : ('a ‑> Sexplib.Sexp.t) ‑> 'a t ‑> Sexplib.Sexp.tval create : ?on_change:('a ‑> unit) ‑> 'a incremental ‑> 'a tWhen calling create ?on_change child, nothing happens until the t is linked
to a parent. see Node.add_dependency for documentation of on_change.
val value : 'a t ‑> 'avalue t reads the value of the child incremental. It can only be used from
the callback of the Expert.Node.t that has t in its set of dependencies.