class_docstr: Shapelet PQ.
code: def __init__(self):
      self._queue = []
      self._index = 0
  
imports: import heapq
  import time
  import warnings
  from itertools import zip_longest
  from operator import itemgetter
  import numpy
  import pandas
  from joblib import Parallel, delayed
  from sklearn import preprocessing
  from sklearn.utils import check_random_state
  from sklearn.utils.multiclass import class_distribution
  from sktime.transformations.base import BaseTransformer
  from sktime.utils.validation import check_n_jobs
label_desc: Use image node_id 1 to create a new ShapeletPQ object  with example: obj = ShapeletPQ()