fails:Array#sample selects a random value from the array
fails:Array#sample returns nil for empty arrays
fails:Array#sample passed a number n as an argument raises ArgumentError for a negative n
fails:Array#sample passed a number n as an argument returns different random values from the array
fails:Array#sample passed a number n as an argument tries to convert n to an Integer using #to_int
fails:Array#sample passed a number n as an argument returns all values with n big enough
fails:Array#sample passed a number n as an argument returns [] for empty arrays or if n <= 0
fails:Array#sample passed a number n as an argument does not return subclass instances with Array subclass
