code: def test_fixed_node_fruchterman_reingold(self):
      # Dense version (numpy based)
      pos = nx.circular_layout(self.Gi)
      npos = nx.spring_layout(self.Gi, pos=pos, fixed=[(0, 0)])
      assert tuple(pos[(0, 0)]) == tuple(npos[(0, 0)])
      # Sparse version (scipy based)
      pos = nx.circular_layout(self.bigG)
      npos = nx.spring_layout(self.bigG, pos=pos, fixed=[(0, 0)])
      for axis in range(2):
          assert pos[(0, 0)][axis] == pytest.approx(
              npos[(0, 0)][axis], abs=1e-7
          )
  
imports: import pytest
  import networkx
label_desc: Use image node_id 18 for calling the TestLayout obj's underlying member method code with example usage: obj.test_fixed_node_fruchterman_reingold() without return types