docs: def get_parameters(self):
          """stub"""
          if not self.is_parameterized():
              raise IllegalState()
          if not self.get_text('python_script'):
              return dict()
          import imp
          from types import ModuleType, FunctionType
          script_module = imp.new_module('script_module')
          exec(self.get_text('python_script').text, script_module.__dict__)
          params = dict()
          for attr in dir(script_module):
              if (not isinstance(getattr(script_module, attr), ModuleType) and
                      not isinstance(getattr(script_module, attr), FunctionType) and
                      not attr.startswith('__')):
                  params[attr] = getattr(script_module, attr)
          return params