'Retrieve page number of a given Destination object
:param Destination destination: The destination to get page number.
Should be an instance of
:class:`Destination<PyPDF2.pdf.Destination>`
:return: the page number or -1 if page not found
:rtype: int'

def getDestinationPageNumber(self, destination):

    indirectRef = destination.page
    ret = self._getPageNumberByIndirect(indirectRef)
    return ret
