Somewhere early, define this:
Database.SetInitializer(new MyInitializer());
This will be a custom implementation of IDatabaseInitializer that enherits from a well-known strategy:
//Invoke *early*, eg from a Boottrapper:
//Database.SetInitializer<GraphContext>(new GraphInitializer());
public class MyInitializer : DropCreateDatabaseIfModelChanges<TestContext>
{
...
protected override void Seed(GraphContext context)
{
BuildCountryLookup(context);
//etc
}
}