i have written this test class but I am getting error like this
@istest
public class SplitTriggerTest {
    @testsetup
    Public static void split(){
        Account acc = new Account();
        acc.Name = 'Test Account1';
           insert acc;
        
        Equipment__c eqp = new Equipment__c();
        eqp.Name = 'E1';
        eqp.Category__c = 'B';
        insert eqp;
        
        Opportunity__c opp = new Opportunity__c();
        opp.Opportunity_Name__c = 'Test A';
        opp.Stage__c = 'Prospect';
        opp.CommercialFrom__c = 'Rent Alpha Private Limited';
        opp.Account__c = acc.id;
        insert opp;
        
        Opportunity_Product__c op = new Opportunity_Product__c();
        op.Equipment__c = eqp.id; 
        op.Opportunity__c = opp.id;
        op.Tenure_in_months__c = 1234;
        insert op;
        
        Split__c sp = new Split__c();
        sp.Amount__c = 1234;
        sp.Reason_for_Loss__c = 'Competition';
        sp.Competitor__c = 'Hewlett Packard';
        sp.Offer_Equipment__c = op.id;
        insert sp;       
    }
    @isTest
    Private static void splitamount(){
        Split__c spl = [Select id, Name from Split__c Limit 1];
        apexpages.StandardController sc = new apexpages.StandardController(sp);
        SplitTrigger c = new SplitTrigger(sc);
        
    }

}