By default db4o doesn't store static fields. With this setting you force db4o to also store the value of the static fields. Note that only reference types are stored. Value-types like ints, longs etc are not persisted.
In general you shouldn't store static fields, because this can lead to unexpected behaviors. It's mostly useful for enumeration classes. See "Storing Static Fields"
EmbeddedConfiguration configuration = Db4oEmbedded.newConfiguration();
configuration.common().objectClass(Person.class).persistStaticFieldValues();