fails:Kernel#puts is a private method
fails:Kernel#puts writes just a newline when given no args
fails:Kernel#puts writes a newline when given nil as an arg
fails:Kernel#puts calls to_s before writing non-string objects
fails:Kernel#puts writes each arg if given several
fails:Kernel#puts flattens a nested array before writing it
fails:Kernel#puts writes [...] for a recursive array arg
fails:Kernel#puts writes a newline after objects that do not end in newlines
fails:Kernel#puts does not write a newline after objects that end in newlines
fails:Kernel#puts ignores the $/ separator global
