class_docstr: Unit tests for :func:`networkx.generators.lattice.hypercube_graph`
code: def test_degree_distribution(self):
      for n in range(1, 10):
          G = nx.hypercube_graph(n)
          expected_histogram = [0] * n + [2**n]
          assert nx.degree_histogram(G) == expected_histogram
  
imports: from itertools import product
  import pytest
  import networkx
  from networkx.utils import edges_equal
label_desc: Use image node_id 2 for calling the TestHypercubeGraph obj's underlying member method code with example usage: obj.test_degree_distribution() without return types