class_docstr: Truncate unequal length panels to lower/upper bounds.
  
  Truncates all series in panel between lower/upper range bounds.
  
  Parameters
  ----------
  lower : int, optional (default=None) bottom range of the values to
              truncate can also be used to truncate to a specific length
              if None, will find the shortest sequence and use instead.
  upper : int, optional (default=None) upper range, only required when
              paired with lower.
              This is used to calculate the range between. exclusive.
              if None, will truncate from 0 to the lower bound.
code: def __init__(self, lower=None, upper=None):
      self.lower = lower
      self.upper = upper
      self.min_length = lower
      super().__init__()
  
file_path: sktime/sktime/transformations/panel/truncation.py
imports: import numpy
  import pandas
  from sktime.transformations.base import BaseTransformer
label_desc: Use image node_id 1 to create a new TruncationTransformer object from inherited base classes: BaseTransformer with example: obj = TruncationTransformer(lower, upper)