code: def testValidSpec(self):
      try:
          x = Spec(description="123", singleNodeOnly=True)
          x.invariant()
  
          x = Spec(description="123", singleNodeOnly=True)
          x.commands = dict(
              command1=CommandSpec("A command"),
              command2=CommandSpec("Another command"),
          )
          x.invariant()
      except:
          self.fail("Got unexpected exception")
  
file_path: nupic-legacy/tests/unit/nupic/regions/regions_spec_test.py
imports: import unittest2
  from nupic.regions.spec import Spec, InputSpec, OutputSpec, ParameterSpec, CommandSpec
label_desc: Use image node_id 10 for calling the KNNAnomalyClassifierRegionTest obj's underlying member method code with example usage: obj.testValidSpec() without return types