code: def test_length(self):
      for i in list(range(13)) + [31, 47, 62, 63, 64, 72]:
          G = nx.random_graphs.gnm_random_graph(i, i * i // 4, seed=i)
          # Strip the trailing newline.
          gstr = g6.to_graph6_bytes(G, header=False).rstrip()
          assert len(gstr) == ((i - 1) * i // 2 + 5) // 6 + (
              1 if i < 63 else 4
          )
  
imports: from io import BytesIO
  import pytest
  import networkx
  import networkx.readwrite.graph6
  from networkx.utils import edges_equal, nodes_equal
label_desc: Use image node_id 8 for calling the TestToGraph6Bytes obj's underlying member method code with example usage: obj.test_length() without return types