Angular2 and typescript - how to add an array to a array from promise?

In my controller, I make a rest call to create my table. I need to append some fixed rows and I dont know how to do it.

I want something like this:

export class Environment { id: string; name: string; }

environments: any[]; 
production = new Environment('1', 'production');
development = new Environment('2', 'development');

    ngOnInit(){
            this.environmentService.getEnvironments()
                .subscribe(environments => this.environments = environments,null,() => { this.isLoading = false; });

        } 

So how do I add an array to the promise result?"

  [this.production,this.development] + this.environments;

Results of proposed solution:

 staging: Environment = {
        id: '111',
        name: 'staging'
};

environments = [this.staging];

[ { "id": "111", "name": "staging" }, [ { "id": "86aa96e8-0383-4bce-b833-be3c21f47306", "name": "cloud" } ] ]

The name with cloud is from the server. So close but should look like this:

[ { "id": "111", "name": "staging" },{ "id": "86aa96e8-0383-4bce-b833-be3c21f47306", "name": "cloud" } ]

This worked but is there a better way?:

this.environmentService.getEnvironments()
            .subscribe(environments => {
                for (var i = 0; environments.length > i; i++) 
                { this.environments.push(environments[i])}

            },null,() => { this.isLoading = false; });