public async Task CollaboratorLeavesProject(string projectName)
{
await Groups.RemoveFromGroupAsync(Context.ConnectionId, projectName);
var(leftFrom, project) = await _editorService.Leave(projectName, Context.User);
if (leftFrom)
{
await _projectsHubContext.Clients.All.SendAsync(nameof(ProjectsHub.CollaboratorJoinsProject), project);
}
}