Type checking on google apps script platform

Question

Is there a way to check againts built-in types in google apps script? I don't know how to access contructors of built-in types. So I can't use instaceof operator.

For example Profile (https://developers.google.com/apps-script/class_analytics_v3_schema_profile )

function getReportDataForProfile(profile) {
if (profile instanceof Profile) // Profile is undefined...
...
}

Also what is a litle confusing: When I get an instance of Profile (in variable profile)

profile.constructor // is undefined

Answer 1

After observing the output of Logger.log() it is clear that for most built-in Google Apps objects the output of the toString() method is the Class name:

var sheet = SpreadsheetApp.getActiveSheet()
if (typeof sheet == 'object')
{
    Logger.log(  String(sheet)     ) // 'Sheet'
    Logger.log(  ''+sheet          ) // 'Sheet'
    Logger.log(  sheet.toString()  ) // 'Sheet'
    Logger.log(  sheet             ) // 'Sheet' (the Logger object automatically calls toString() for objects)
}

So any of the above can be used to test the type of the object (except the last one example that obviously works only with the Logger)