Example can not be used.

[TheHuangs]

@mitenmistry , When I use the command "python iterative.py model2 Test" to run the example model model2, python gives such error:
ERROR: evaluating object as numeric value: Last_stage
(object: <class 'pyomo.core.base.param.SimpleParam'>)
Invalid parameter value: Last_stage[None] = 'Number_stages + 1', value
type=<class 'pyomo.core.expr.numeric_expr.NPV_SumExpression'>.
Value not in parameter domain PositiveIntegers
ERROR: Constructing component 'K' from data=None failed:
ValueError: Invalid parameter value: Last_stage[None] = 'Number_stages
+ 1', value type=<class
'pyomo.core.expr.numeric_expr.NPV_SumExpression'>.
Value not in parameter domain PositiveIntegers
Traceback (most recent call last):
File "iterative.py", line 102, in
model = initialise_hx_model(datafile)
File "E:\Softwares\MyPyomoExamp\hens-master\adaptive_model_mixer\lib\iterations_helper.py", line 215, in initialise_hx_model
instance = model.create_instance(datafile)
File "C:\Python36\lib\site-packages\pyomo\core\base\PyomoModel.py", line 735, in create_instance
profile_memory=profile_memory )
File "C:\Python36\lib\site-packages\pyomo\core\base\PyomoModel.py", line 818, in load
profile_memory=profile_memory)
File "C:\Python36\lib\site-packages\pyomo\core\base\PyomoModel.py", line 882, in _load_model_data
self._initialize_component(modeldata, namespaces, component_name, profile_memory)
File "C:\Python36\lib\site-packages\pyomo\core\base\PyomoModel.py", line 936, in _initialize_component
declaration.construct(data)
File "C:\Python36\lib\site-packages\pyomo\core\base\rangeset.py", line 83, in construct
self._end_val = value(self._end)
File "C:\Python36\lib\site-packages\pyomo\core\expr\numvalue.py", line 226, in value
tmp = obj(exception=True)
File "C:\Python36\lib\site-packages\pyomo\core\base\param.py", line 975, in call
return self[None]
File "C:\Python36\lib\site-packages\pyomo\core\base\indexed_component.py", line 348, in getitem
return self._getitem_when_not_present(index)
File "C:\Python36\lib\site-packages\pyomo\core\base\param.py", line 525, in _getitem_when_not_present
self._validate_value(index, val, _check_value_domain)
File "C:\Python36\lib\site-packages\pyomo\core\base\param.py", line 621, in _validate_value
(self.name, index, value, type(value), self.domain.name))
ValueError: Invalid parameter value: Last_stage[None] = 'Number_stages + 1', value type=<class 'pyomo.core.expr.numeric_expr.NPV_SumExpression'>.
Value not in parameter domain PositiveIntegers

hope that you can give some suggestions.