QueryObjectGeneratorImpl.getAutoGeneratedKeys() can generate a ClassCastExcedption as it does not validate that the datatype of the returned autogenerated key can be stored in the
data type of the field of the DataSet.

Example
create a table using Derby with a identity column which is an Integer.

Create the DataSet for the Autogenerated Keys to also be an Integer

When you run a sample program which does this, you will get a ClassCastException back as Derby is returning a BigDecimal.