code: def generate_sequences(sequence_length, num_sequences):
      for i in range(num_sequences):
          seq = [
              np.random.randint(10)
              for x in range(np.random.randint(1, sequence_length + 1))
          ]
          yield (seq, seq)
  
imports: import os
  import pytest
  import tempfile
  import numpy
  import deepchem
  import scipy.io
  from flaky import flaky
  from sklearn.ensemble import RandomForestClassifier
  from deepchem.molnet.load_function.chembl25_datasets import CHEMBL25_TASKS
  from deepchem.feat import create_char_to_idx
label_desc: Use image node_id 21 for calling a global function with example usage: generate_sequences(sequence_length, num_sequences) without return types