# Generates a thread consisting of a top level message and 'length'
# replies. The subject of the top message 'subject: top message"
# and the subject of the nth reply in the thread is "subject: reply n"
-generate_thread ()
-{
+generate_thread () {
local subject="$1"
local length="$2"
generate_message '[subject]="'"${subject}: top message"'"' '[body]="'"body of top message"'"'