### Question:
ForceJPAClassGenerator extends AbstractCodeGenerator { public void setPackageName(String packageName) { if (packageName != null) { validatePackageName(packageName); } this.packageName = packageName; }  void setPackageName(String packageName); @Override final ObjectFilter getObjectFilter(); final void setObjectFilter(ObjectFilter objectFilter); @Override final FieldFilter getFieldFilter(); final void setFieldFilter(FieldFilter fieldFilter);  }### Answer:
@Test public void testGenerateWithInvalidPackageName() throws ConnectionException, IOException { ForceJPAClassGenerator generator = new ForceJPAClassGenerator(); try { generator.setPackageName("1"); fail("Should not be able to set an invalid package name"); } catch (IllegalArgumentException expected) { assertEquals(expected.getMessage(), "Invalid package name: 1"); } }