fails:Method#parameters returns [[:rest,:a],[:req,:b]] for a method expecting a splat argument ('a') and a required argument ('b')
fails:Method#parameters returns [[:rest,:a],[:req,:b],[:req,:c]] for a method expecting a splat argument ('a') and two required arguments ('b','c')
fails:Method#parameters returns [[:rest,:a],[:req,:b],[:block,:c]] for a method expecting a splat argument ('a'), a required argument ('b'), and a block ('c')
