def die_rolls(number_of_words)
      # The Diceware method specifies five rolls of the die for each word.
      die_rolls_per_word = 5
      total_die_rolls = number_of_words * die_rolls_per_word
      die_roll_sequence = generate_random_numbers(total_die_rolls, 6, 1)
      group_die_rolls(die_roll_sequence, number_of_words, die_rolls_per_word)
    end
def die_rolls(number_of_words)
      # The Diceware method specifies five rolls of the die for each word.
      die_rolls_per_word = 5
      total_die_rolls = number_of_words * die_rolls_per_word
      die_roll_sequence = generate_random_numbers(total_die_rolls, 6, 1)
      group_die_rolls(die_roll_sequence, number_of_words, die_rolls_per_word)
    end
Returns an array of strings where each string comprises five numeric
 characters, each one representing one roll of a die. The number of
 elements in the array equals the number of words specified for the
 passphrase.
 @param number_of_words [Integer] the desired number of words in the
   passphrase
 @return [Array<String>] an array of strings each one of which represents
   five rolls of a die