src/vs/workbench/api/common/extHostTerminalService.ts/BaseExtHostTerminalService/getEnvironmentVariableCollection
class BaseExtHostTerminalService:	public getEnvironmentVariableCollection(extension: IExtensionDescription): vscode.EnvironmentVariableCollection {
		let collection = this._environmentVariableCollections.get(extension.identifier.value);
		if (!collection) {
			collection = new EnvironmentVariableCollection();
			this._setEnvironmentVariableCollection(extension.identifier.value, collection);
		}
		return collection;
	}