code: def testValidCommandSpec(self):
      try:
          x = CommandSpec("")
          x.invariant()
          x = CommandSpec(description="")
          x.invariant()
          x = CommandSpec(description="this is a 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 8 for calling the KNNAnomalyClassifierRegionTest obj's underlying member method code with example usage: obj.testValidCommandSpec() without return types