Serializing object containing a ctor function causes crash

[utillity]

I am trying to serialize a list of objects, which contain the constructor to a sub-object for internal reasons in an attribute _cfgType.

class LensValuedSettingArgs {}
...
FocusPos = new LensValuedSetting({ _cfgType:LensValuedSettingArgs, ... })

this causes a runtime error, as this property cannot be serialized.

TypeError: Cannot read property 'replace' of undefined
  at node_modules/json2csv/lib/json2csv.js:275:50
  at Array.forEach (native)
  at node_modules/json2csv/lib/json2csv.js:215:21
  at Array.forEach (native)
  at createColumnContent (node_modules/json2csv/lib/json2csv.js:209:50)
  at Object.<anonymous>.module.exports (node_modules/json2csv/lib/json2csv.js:60:13)

Since the object hierarchy is deep and complex, I would like to be able to specify ignoreFields instead of fields, or the parser should gracefully ignore attributes containing a function