code: def validate_intervals(intervals):
      
  
      # Validate interval shape
      if intervals.ndim != 2 or intervals.shape[1] != 2:
          raise ValueError('Intervals should be n-by-2 numpy ndarray, '
                           'but shape={}'.format(intervals.shape))
  
      # Make sure no times are negative
      if (intervals < 0).any():
          raise ValueError('Negative interval times found')
  
      # Make sure all intervals have strictly positive duration
      if (intervals[:, 1] <= intervals[:, 0]).any():
          raise ValueError('All interval durations must be strictly positive')
docs: Checks that an (n, 2) interval ndarray is well-formed, and raises errors
      if not.
  
      Parameters
      ----------
      intervals : np.ndarray, shape=(n, 2)
          Array of interval start/end locations.