Tests capturing MHTML snapshots.
Capturing without specified format:
From:
Subject:
Content-Type: multipart/related;
type="text/html";
<------MultipartBoundary-->Content-Type: text/html
<------MultipartBoundary-->
Capturing with format: foo
{
error : {
code : -32000
message : Unsupported snapshot format
}
id :
sessionId :
}