### Question:
GlobalBiasModel implements BiasModel, Serializable { @Override public double getIntercept() { return intercept; } GlobalBiasModel(double bias); @Override double getIntercept(); @Override double getUserBias(long user); @Override double getItemBias(long item); @Override Long2DoubleMap getUserBiases(LongSet users); @Override Long2DoubleMap getItemBiases(LongSet items); @Override Long2DoubleMap getUserBiases(); @Override Long2DoubleMap getItemBiases();  }### Answer:
@Test public void testComputeGlobalMean() { EntityFactory efac = new EntityFactory(); EntityCollectionDAOBuilder daoBuilder = new EntityCollectionDAOBuilder(); daoBuilder.addEntities(efac.rating(100, 200, 3.0), efac.rating(101, 200, 4.0), efac.rating(101, 201, 2.5), efac.rating(102, 203, 4.5)); Provider<GlobalBiasModel> biasProvider = new GlobalAverageRatingBiasModelProvider(daoBuilder.build()); BiasModel model = biasProvider.get(); assertThat(model.getIntercept(), closeTo(3.5, 1.0e-1)); }