I have 2 ArrayLists in Java: 

```
mProductList = new ArrayList<ProductSample>();
mProductList2 = new ArrayList<ProductSample>();

mProductList = productSampleList;

mProductList2 = productSampleList;

mProductList2 .remove(3);

```

The productSampleList has size 5.
Why after this segment code is executed. mProductList has size 4?

Does we have any way to avoid this? I want the mProductList have size 5 as the same as productSampleList.  

 Thanks!