Function get

get(
    graph: Readonly,
    key: string,
):
    | undefined
    | Readonly<
        {
            id: string;
            out: readonly Readonly<{ id: string; weight?: number }>[];
        },
    >
Returns Vertex under key, or undefined if not found.
```
// Same as
g.vertices.get(key)
```
Parameters
- graph: Readonly
- key: string
Returns
    | undefined
    | Readonly<
        {
            id: string;
            out: readonly Readonly<{ id: string; weight?: number }>[];
        },
    >