you could add: include(assert)
assert_var(message_type message var) - is var defined?
assert_ndef(message_type message var) - is not var defined?
assert_empty(message_type message var) - is var empty?
assert_empty(message_type message var) - is not var not empty?
assert_eq(message_type message var1 var2)
assert_neq(message_type message var1 var2)
…
Something else