Public getter for ParamDefinition.unit field

src/param/param-definition.ts

@@ -145,6 +145,10 @@ export class ParamDefinition implements INamedIterableValues, IObservable {
         return this.nubUid + "_" + this._symbol;
     }
 
+    public get unit(): string {
+        return this._unit;
+    }
+
     /**
      * pointer to the ComputeNode (usually Nub) that uses the ParamsEquation that
      * uses this ParamDefinition; for Section params, this means the Nub enclosing