I'm currently writing a test class and keep getting "Method does not exist or incorrect signature errors... I'm not certain or confident that I am writing the test class properly...



public class SetEMT {
    ApexPages.StandardController stdCtrl;
    public SetEMT(ApexPages.StandardController controller) {
        stdCtrl=controller;
    }
    List<EmailTemplate> mmts;
    public String mmtid {get; set;}
    public String mmtname {get; set;}
    public String folder {get; set;}
    
    public List<EmailTemplate> getTemplates() {

        if(mmts == null) mmts = [select name, description from EmailTemplate order by Name];              
        return mmts;
    }
    
    public void changeTemplates() {
      if(folder != null && !folder.equals('')) mmts = [select name, description from EmailTemplate where FolderId = :folder order by Name];
      else mmts = [select name, description from EmailTemplate order by Name];
    }
    
    public List<SelectOption> getFolders() {
        List<Folder> folders = [select name, Id from Folder where Type = 'Email' order by name];
        List<SelectOption> options = new List<SelectOption>();
        options.add(new SelectOption('',''));
        for (Folder f : folders) {
            options.add(new SelectOption(f.Id,f.Name));
        }
        return options;
    }
    public void setTemplate() {
        EAST_Mailing__c mailing = (EAST_Mailing__c)stdCtrl.getRecord();
        mailing.PreApprovedEmailTemplateName__c = mmtname;
        mailing.PreApprovedEmailTemplateLink__c = URL.getSalesforceBaseUrl().toExternalForm() + '/' + mmtid;
        update mailing;
    }
}



@ istest (SeeAllData=true)
public class SetEMTTest
{
    private static testmethod void validate(){
        
        List<EmailTemplate> eList = new List<EmailTemplate>();
        EmailTemplate e = new EmailTemplate (Name = 'Test Template', TemplateType= 'Text');   
        eList.add(e);
       
        ApexPages.StandardSetController setCtr = new ApexPages.StandardSetController(eList);
        SetEMT.setSelected(new EmailTemplate[]{e});
        MassUpdateSimpleController controller = new MassUpdateSimpleController(SetEMT);
        
        controller.getTemplates();
        
        System.assert(controller.getTemplates()!=null);
        
    }
    
}