Constructs a new ReactiveMap with the given initial content.
Optional
// Emptyconst map1 = reactiveMap<string, number>();// With initial contentconst map2 = reactiveMap<string, number>([["foo", 1], ["bar", 2]]); Copy
// Emptyconst map1 = reactiveMap<string, number>();// With initial contentconst map2 = reactiveMap<string, number>([["foo", 1], ["bar", 2]]);
Constructs a new ReactiveMap with the given initial content.