code: def test_iter_slice():
      i = iter_slice(b"12345678", 3)
      assert next(i) == (b"123", False)
      assert next(i) == (b"456", False)
      assert next(i) == (b"78", True)
      with pytest.raises(StopIteration):
          next(i)
  
      i = iter_slice(b"123456", 3)
      assert next(i) == (b"123", False)
      assert next(i) == (b"456", True)
      with pytest.raises(StopIteration):
          next(i)
  
imports: import pytest
  from bplustree.utils import pairwise, iter_slice
label_desc: Use image node_id 2 for calling a global function with example usage: test_iter_slice() without return types