@Test
public void writeTo() throws Exception {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
builder.writeTo(baos, rawSession);
String eml = save(new String(baos.toByteArray().toByteArray()));
assertThat(eml, containsAllRegex( //
"Subject:\\s*" + REGEX_EOL, //
"Content-Type: text/plain; charset=us-ascii" + REGEX_EOL, //
REGEX_EOL + REGEX_EOL + "$"));