src/vs/workbench/api/common/extHostTerminalService.ts/EnvironmentVariableCollection/forEach
class EnvironmentVariableCollection:	forEach(callback: (variable: string, mutator: vscode.EnvironmentVariableMutator, collection: vscode.EnvironmentVariableCollection) => any, thisArg?: any): void {
		this.map.forEach((value, key) => callback.call(thisArg, key, value, this));
	}