Cek duplicate record and remove before drag and drop

beforedrop:function(node,data,model,dropPosition,fn, O ) {       
        var drop_array  = Ext.pluck(data.records,'data'); 
     Ext.Array.each(drop_array, function(name, index, countriesItSelf) {
         secondGridStore.each(function(rec,idx) {
       if(rec.data.BUYER_ID == name['BUYER_ID']) 
        secondGridStore.removeAt(idx);    
      
         });    
     });
    }