When I want get `Object` by `key` I have `undefined` each all element.

My Map : 

```
nodesMaps : Map<number, Object> = [
{ key: "1", value: Object },
{ key: "2", value: Object },
{ key: "3", value: Object },
]

```

When I want get value of this map :

```
this.nodesMaps.get(1) // return undefined
this.nodesMaps.get("1") // return undefined

```