flow like the river

VISUALIZACION/node_modules/ngraph.graph/CHANGELOG.md

@@ -0,0 +1,39 @@
+# v20.0.0
+
+The changelog is introduced. Justification for it is that there is a breaking change
+in the library, and I wanted to call it out here.
+
+### getLink(fromId, toId) / getLinks(nodeId)
+
+`graph.getLinks(nodeId)` now returns a `Set` object. Previous version of the method
+returned an `Array`. 
+
+Pre `v20.0.0` library versions, `getLink(fromId, toId)` operation had `O(deg(fromId))` time performance.
+
+In `v20.0.0` the links are manged via sets, driving the `getLink()` performance down to `O(1)`.
+
+#### How to update?
+
+If your library used `graph.getLinks(fromId).length` constructs, you'll need to change that to
+`graph.getLinks(fromId).size`
+
+### addLink(fromId, toId, data)
+
+For non-multigraphs, this method will now act similar to `addNode(nodeId, data)`. If link is 
+already present in the graph it will replace old `link.data` with new `data`. Otherwise a new link will be created.
+
+Prior versions of the library always create a new link and clients were required to check link
+presence to avoid duplicates.
+
+```
+// this code is no longer necessary:
+if (graph.hasLink(fromId, toId) || graph.hasLink(toId, fromId)) {
+  graph.addLink(fromId, toId, 42);
+}
+
+// In version v20.0.0 it is equivalent to:
+graph.addLink(fromId, toId, 42);
+```
+
+For multigraphs this method will act the same way as before - a new link will always be created.
+