src/vs/workbench/api/common/extHostTerminalService.ts/EnvironmentVariableCollection/_setIfDiffers
class EnvironmentVariableCollection:	private _setIfDiffers(variable: string, mutator: vscode.EnvironmentVariableMutator): void {
		const current = this.map.get(variable);
		if (!current || current.value !== mutator.value || current.type !== mutator.type) {
			this.map.set(variable, mutator);
			this._onDidChangeCollection.fire();
		}
	}