def max_sequence_depth(comma_sequence, current_depth)
      # Sequence contains interpolation; assume a depth of 1
      return current_depth + 1 unless comma_sequence

      comma_sequence.members.map { |sequence| sequence_depth(sequence, current_depth) }.max
    end
def max_sequence_depth(comma_sequence, current_depth)
      # Sequence contains interpolation; assume a depth of 1
      return current_depth + 1 unless comma_sequence

      comma_sequence.members.map { |sequence| sequence_depth(sequence, current_depth) }.max
    end
Find the maximum depth of all sequences in a comma sequence.