Brain Dump 7 - Remove User from group in SharePoint

Clue is in the title

In essence below is a method that will remove a user from a group in SharePoint.

User can be of the form domain\user or user@domain

public bool RemoveUserFromSharePointGroup(string userName, string groupName)
{
 var principal = Microsoft.SharePoint.Client.Utilities.Utility.ResolvePrincipal(context, context.Web, userName,
  Microsoft.SharePoint.Client.Utilities.PrincipalType.User, Microsoft.SharePoint.Client.Utilities.PrincipalSource.All,
  context.Web.SiteUsers, false);
  
 context.ExecuteQuery();
 
 if (principal.Value != null)
 {
  string login = principal.Value.LoginName;
  GroupCollection siteGroups = context.Web.SiteGroups;
  Group group = siteGroups.GetByName(groupName);
 
  var query = context.LoadQuery(group.Users.Where(usr => usr.LoginName == login).Include(u => u.LoginName));
 
  context.ExecuteQuery();
 
  User user = query.SingleOrDefault();
 
  if (user != null)
  {
   group.Users.RemoveByLoginName(user.LoginName);
  }
 
  context.ExecuteQuery();
 
 }
}