docs: def next_interval(self, interval):
          """
          Given a value of an interval, this function returns the 
          next interval value
          """
          index = np.where(self.intervals == interval)
          if index[0][0] + 1 < len(self.intervals):
              return self.intervals[index[0][0] + 1]
          else:
              raise IndexError("Ran out of intervals!")