code: def test_pydotprint():
      def f_pow2(x_tm1):
          return 2 * x_tm1
  
      state = scalar("state")
      n_steps = iscalar("nsteps")
      output, updates = pytensor.scan(
          f_pow2,
          [],
          state,
          [],
          n_steps=n_steps,
          truncate_gradient=-1,
          go_backwards=False,
      )
      f = pytensor.function(
          [state, n_steps],
          output,
          updates=updates,
          allow_input_downcast=True,
      )
      pydotprint(output, scan_graphs=True)
      pydotprint(f, scan_graphs=True)
  
file_path: pytensor/tests/scan/test_printing.py
imports: import numpy
  import pytest
  import pytensor
  import pytensor.tensor
  from pytensor.configdefaults import config
  from pytensor.graph.fg import FunctionGraph
  from pytensor.printing import debugprint, pydot_imported, pydotprint
  from pytensor.tensor.type import dvector, iscalar, scalar, vector
label_desc: Use image node_id 8 for calling a global function with example usage: test_pydotprint() and returns: unknown