Equivalent of Rest $filter in CSOM Caml query

Question

I am trying to convert my rest implementation to CSOM.

Rest API for the same : _api/web/sitegroups?$Filter=LoginName%20eq%20'Test_Grp'

Unable to find an equivalent for $filter in lambda expressions.

I have a list of groupNames and I need to fetch only those groups from SharePoint.

The below snippet throws a ClientRequestException that

'The 'Contains' member cannot be used in the expression.

How can I retrieve only the groups whose names are in my list?

  using (var clientContext = new ClientContext(ServerUrl))
  {
       GroupCollection collGroup = clientContext.Web.SiteGroups;

            clientContext.Load(collGroup);

            clientContext.Load(collGroup,
          groups => groups.Include(
              group => group.LoginName,
             group => group.Title,
          group => group.Id), group => group.Where(i => names.Contains((string)i.LoginName)));
            clientContext.ExecuteQuery();
  }

Answer 1

REST request: /_api/web/sitegroups?$filter=LoginName eq '<group name>' could be converted to the following CSOM equivalent:

using (var context =  new ClientContext(webUri))
{         
      var result = context.LoadQuery(context.Web.SiteGroups.Where(g => g.LoginName == groupName));
      context.ExecuteQuery();
      var foundGroup = result.FirstOrDefault(); //get first result. Use .ToList() to retrieve all results  

      if (foundGroup != null) 
           Console.WriteLine(foundGroup.Title);

}