package bonsai

Wraps each node in a Computation.t with calls to start_timer and stop_timer. The string passed to both these is intended to be the names for performance entries sent to the browser. The strings contain the Node_path to which the time corresponds. When these strings eventually get retrieved via a PerformanceObserver, the id in the string can be retrieved via Node_path.extract_from_entry_label. (We do things this way because we want also want to include the node_type in this string as well, so that looking at measurements in Chrome's profiling tools is easier).

on_graph_update is called whenever the graph info gets updated. For example (in fact, the only example), when a Lazy gets forced, we must expand the graph to include what was inside the Lazy.