In ObjectFactory.java:
The ObjectFactory class is part of the primer.po package.
ObjectFactory provides factory methods for instantiating Java interfaces representing XML content in the Java content tree.
Method names are generated by concatenating:
The string constant create.
If the Java content interface is nested within another interface, then the concatenation of all outer Java class names.
The name of the Java content interface.
For example, in this case, for the Java interface primer.po.Items.ItemType, ObjectFactory creates the method createItemsItemType().