public void PopulateContactFieldsInQuote(list<Quote> quotelist1){

    List<Quote> quoteList = new List<Quote>();
    Map<String, Quote> QuotetoOpportunityIDMap = new Map<String, Quote>();
    for( Quote Qid : quotelist1 )
    {
        QuotetoOpportunityIDMap.put( Qid.OpportunityID, Qid );
    }

    List<OpportunityContactRole> Contactlist = [select OpportunityID, IsPrimary,ContactID,contact.email,contact.phone,contact.fax from OpportunityContactRole where OpportunityID in :QuotetoOpportunityIDMap.keySet() and IsPrimary = true];

    for (OpportunityContactRole oppConrole : Contactlist) {

        Quote quoteToUpdate = QuotetoOpportunityIDMap.get(oppConrole.OpportunityID);

        quoteToUpdate.ContactId = oppConrole.ContactId;
        quoteToUpdate.phone = oppConrole.Contact.phone;
        quoteToUpdate.fax = oppConrole.Contact.fax;
        quoteToUpdate.email = oppConrole.Contact.email;
        quoteList.add(quoteToUpdate);
    }
}

contact c=new contact();
    c.lastname='ctes';
    c.accountid=a.id;
    insert c;

    opportunity o = new opportunity();
    o.name = 'Testoppty';
    o.StageName = 'lead';
    o.CloseDate = date.today();
    o.accountid = a.Id;
    o.Billing_Type__c='Aggregate';
    insert o;

    quote q=new quote();
    q.name='tesq';
    q.contactid=c.id;
    q.email='g@gg.com';
    insert q;

}