public void have_all_fields_filled()
{
var writer = XmlWriter.Create(new MemoryStream());
var entry = new EntryElement();
Assert.Throws <AtomSpecificationViolationException>(() => entry.WriteXml(writer));
entry.SetTitle("test #0");
Assert.Throws <AtomSpecificationViolationException>(() => entry.WriteXml(writer));
entry.SetId("guid");
Assert.Throws <AtomSpecificationViolationException>(() => entry.WriteXml(writer));
entry.SetUpdated(DateTime.UtcNow);
Assert.Throws <AtomSpecificationViolationException>(() => entry.WriteXml(writer));
entry.SetAuthor(AtomSpecs.Author);
Assert.Throws <AtomSpecificationViolationException>(() => entry.WriteXml(writer));
entry.SetSummary("Entry #0");
Assert.DoesNotThrow(() => entry.WriteXml(writer));
writer.Close();
}