code: def test_remove_output_empty(self):
      var1 = MyVariable("var1")
      var2 = MyVariable("var2")
      op1_out = op1(var1)
      op3_out = op3(op1_out, var2)
      fg = FunctionGraph([var1, var2], [op3_out], clone=False)
  
      fg.remove_output(0)
      fg.check_integrity()
  
      assert fg.inputs == [var1, var2]
      assert not fg.apply_nodes
      assert op1_out not in fg.clients
      assert not any(
          op1_out.owner in clients
          for clients in sum(fg.clients.values(), [])
      )
      assert not any(
          op3_out.owner in clients
          for clients in sum(fg.clients.values(), [])
      )
  
imports: import pickle
  import numpy
  import pytest
  from pytensor.configdefaults import config
  from pytensor.graph.basic import NominalVariable
  from pytensor.graph.fg import FunctionGraph
  from pytensor.graph.utils import MissingInputError
  from tests.graph.utils import MyConstant, MyOp, MyType, MyVariable, MyVariable2, op1, op2, op3
label_desc: Use image node_id 22 for calling the TestFunctionGraph obj's underlying member method code with example usage: obj.test_remove_output_empty() without return types