code: def test_batch_generator():
      size = 10
      batch_size = 6
      a = list(range(size))
      b = np.arange(size)
  
      class TestDataset(Dataset):
          def read(self):
              return [
                  Graph(
                      x=np.random.rand(n, 2),
                      a=np.random.randint(0, 2, (n, n)),
                      y=np.array([0.0, 1.0]),
                  )
                  for n in range(size)
              ]
  
      c = TestDataset()
  
      batches = batch_generator(
          [a, b, c], batch_size=batch_size, epochs=10
      )
      for batch in batches:
          a_, b_, c_ = batch
          for i in range(len(a_)):
              assert a_[i] == b_[i] == c_[i].n_nodes
  
imports: import numpy
  import scipy.sparse
  from spektral.data import Dataset, Graph
  from spektral.data.utils import batch_generator, to_batch, to_disjoint
label_desc: Use image node_id 3 for calling a global function with example usage: test_batch_generator() and returns: unknown