add test: echo a seq with a nil value
add test: echo a seq with a nil value

jfhg/Nim,tulayang/Nim,russpowers/Nim,russpowers/Nim,tulayang/Nim,tulayang/Nim,jfhg/Nim,dom96/Nim,jfhg/Nim,dom96/Nim,jfhg/Nim,russpowers/Nim,russpowers/Nim,jfhg/Nim,jfhg/Nim,tulayang/Nim,dom96/Nim,dom96/Nim,jfhg/Nim,dom96/Nim,dom96/Nim,russpowers/Nim,tulayang/Nim,tulayang/Nim,dom96/Nim,russpowers/Nim,russpowers/Nim