src/vs/workbench/contrib/terminal/browser/terminalProcessManager.ts/TerminalProcessManager/_onEnvironmentVariableCollectionChange
class TerminalProcessManager:	private _onEnvironmentVariableCollectionChange(newCollection: IMergedEnvironmentVariableCollection): void {
		const diff = this._extEnvironmentVariableCollection!.diff(newCollection);
		if (diff === undefined) {
			return;
		}
		this.environmentVariableInfo = this._instantiationService.createInstance(EnvironmentVariableInfoStale, diff, this._instanceId);
		this._onEnvironmentVariableInfoChange.fire(this.environmentVariableInfo);
	}