I have a trigger that I can't get code coverage on an if statment. What am i doing wrong. 
I can't get code coverage on line 33 "if (a.AccountTeamMembers == Null || a.AccountTeamMembers.isEmpty()

Here's the trigger:

trigger trgAsset on Asset (after insert, after update, after delete) {
	if (trigger.isInsert || trigger.isUpdate){
		/*If the Asset has VersaDoc and the account doesn't have a VersaDoc Project Account Team Member, 
		  it will assign the next VersaDoc Project manager from the assignment groups to the Account Team*/

        Set<id> accountTeamAccountIds = new Set<id>(); // set of accountIDs that have VersaDoc in the asset
	    for (Asset a : Trigger.new){  
	    	if (a.HasVersadoc__c == 1 || a.HasVersadocStudio__c == 1 ) {
        		accountTeamAccountIds.add(a.AccountId); 
       	 	} 	
	    }
        
		list<Assignment_Group_Name__c> asgnGroupNameIDs = [SELECT Id FROM Assignment_Group_Name__c WHERE Name = 'Support - VersaDoc Project Managers' limit 1];
		system.debug('asgnGroupnameIDs is ' + asgnGroupNameIDs);
	
		Assignment_Groups__c[] asgnGroups = new List<Assignment_Groups__c>([SELECT Group_Name__c, User__c, Last_Assignment__c, Millisecond__c 
                                   FROM Assignment_Groups__c 
                                   WHERE Group_Name__c in :asgnGroupNameIds
                                   AND Active__c = 'True' AND User_Active__c = 'True'
                                   ORDER BY Last_Assignment__c, Millisecond__c] );                                    
	
		Integer groupCount = asgnGroups.size();
	
    	System.debug('>>>>>asgnGroups: '+asgnGroups);   
   		if (asgnGroups.isEmpty()) return;                      

		//loop through list of accounts and get the accounts w/o VersaDoc Project Manager
		AccountTeamMember[] NewMembers = new AccountTeamMember[]{};  //list of new team members to add
	    AccountShare[] newShare = new AccountShare[]{};  //list of new shares to add
		Map<id, Account> acctsToUpdate = new Map<id, Account>([Select a.Id, (Select Id, AccountId From AccountTeamMembers WHERE TeamMemberRole = 'VersaDoc Project Manager' limit 1) From Account a Where a.Id in :accountTeamAccountIds]);
		Integer cnt = 0;
	    for (Account a : acctsToUpdate.values()){
	    	if (a.AccountTeamMembers == null || a.AccountTeamMembers.isEmpty()) {
	    		AccountTeamMember TeamMemberAd=new AccountTeamMember();
		        TeamMemberAd.AccountId=a.id;
		        TeamMemberAd.UserId=asgnGroups[cnt].User__c;
		       	TeamMemberAd.TeamMemberRole = 'VersaDoc Project Manager';
		        NewMembers.add(TeamMemberAd);	
		        datetime now = datetime.now();
		        asgnGroups.get(cnt).Last_Assignment__c=now;
		        asgnGroups.get(cnt).Millisecond__c = now.millisecondGMT(); 
	    		cnt ++;
	    		if (cnt == groupCount){ cnt = 0;}    	
	    	}
	    } 

		//insert any valid members then add their share entry if they were successfully added
	    Database.SaveResult[] lsr = Database.insert(NewMembers,false);
		Integer newcnt=0;
	    for(Database.SaveResult sr:lsr){
			if(!sr.isSuccess()){
				Database.Error emsg = sr.getErrors()[0];
				system.debug('\n\nERROR ADDING TEAM MEMBER:'+emsg);
			}else{
				newShare.add(new AccountShare(UserOrGroupId=NewMembers[newcnt].UserId, AccountId=NewMembers[newcnt].Accountid, AccountAccessLevel='Edit',OpportunityAccessLevel='Edit'));
			}
				newcnt++;			
	    }
	    //insert the new shares
	    Database.SaveResult[] lsr0 =Database.insert(newShare,false); 
	    Integer newcnt0=0;
	    for(Database.SaveResult sr0:lsr0){
			if(!sr0.isSuccess()){
				Database.Error emsg0=sr0.getErrors()[0];
			    system.debug('\n\nERROR ADDING SHARING:'+newShare[newcnt0]+'::'+emsg0);
			}
				newcnt0++;
	    } 
	    // update assignment groups with their LastAssignmentDate
	    update asgnGroups; 	  
    }
}

Heres' the test class

@isTest(SeeAllData=false)
private class testTrgAssetVersaDocTeamAssignment {
    static testMethod void myUnitTest() {
        // create user to run the test a
        User u =  TestDataFactory.createTestRunAsUser('Standard User', 'Sales Assistant');  
        
        System.runAs(u) {  
            // Switch to the runtime 
             Test.StartTest();
            	// TestDataFactory.createProduct('PrinterPresence Gold Level', 'VersaDoc');
                list<Account> printAccts = TestDataFactory.createTestAccounts(2, 'Printers', 'Client');
                system.debug('***** printAccts is ' + printAccts);
                performCreateAssignmentGroups(u.Id);   
                checkVersaDocAccountTeam(printAccts);
                performCreateVersaDocAssets(u.Id, printAccts);  
            Test.StopTest();   
         }
    }
    
    public static void performCreateAssignmentGroups(id createdby){
        Assignment_Group_Name__c agn = TestDataFactory.createAssignmentGroup('Support - VersaDoc Project Managers', 'Account');
        list<User> u = TestDataFactory.createMulitpleUsers(2, 'Standard User-Support VersaDoc', 'Product Support Rep');     
        system.debug('**** user list is' + u);
        TestDataFactory.addUsersToAssigmentGroup(u, agn);
    }   
    
    public static void checkVersaDocAccountTeam(list <Account> accts){
        Map<id, Account> acctsToCheck = new Map<id, Account>([Select a.Id, (Select Id, AccountId From AccountTeamMembers WHERE TeamMemberRole = 'VersaDoc Project Manager' limit 1) From Account a Where a.Id in :accts]);
        List<Id> acct = new list<Id>();
        System.debug('**** acctsToCheck is ' + acctsToCheck);
        for (Account a: acctsToCheck.values()){
            if (a.AccountTeamMembers == null || a.AccountTeamMembers.isEmpty()) {
				system.debug('**** in if statement if for loop ' + acctsToCheck.values());
                acct.add(a.Id);
        	}
        }
        system.assert(acct.size()>0);
    }
    
    public static void performCreateVersaDocAssets(id createdby, List <Account> accts){
        // add PrinterPresence Gold level Asset (Has VersaDoc)
        date now = date.today(); 
        list<Account> acct = [Select Id from Account where id =: accts];
        list<Asset> assts = new list<Asset>();        
        assts = TestDataFactory.createAssets(accts, now, 'PrinterPresence Gold Level', 'Purchased', 310.00, 7500.00);
        system.debug('***** assts is ' + assts);
        
        Map<id, Account> acctTeams = new map<id, Account>([Select a.Id, (Select Id, AccountId, TeamMemberRole From AccountTeamMembers WHERE TeamMemberRole = 'VersaDoc Project Manager' limit 1) From Account a Where a.Id  =:accts]);
        system.debug('**** acctTeams after adding assets is ' + acctTeams);
        for (Account a : acctTeams.values()){
        	if (a.AccountTeamMembers != null && a.AccountTeamMembers.IsEmpty()==false) {   
            System.assertNotEquals(a.AccountTeamMembers, Null);
            }
        } 
        System.assert(acct.size()>0);
    }
}