top level function used for new data processing which attempts
        to find a level in a heirarchy and return the key and filename
        usage res = FindOntology('file')  # returns 'SYSTEM-PC-FILE'

def find_ontology(self, txt):
        """
        top level function used for new data processing which attempts
        to find a level in a heirarchy and return the key and filename
        usage res = FindOntology('file')  # returns 'SYSTEM-PC-FILE'
        """
        totFound = 0
        searchString = txt.upper()
        match = []
        if searchString != '':
            for i in self.lst_subj:
                if searchString in i:
                    totFound = totFound + 1
                    match.append(i)
        if len(match) == 0:
            match.append('_TOP')
        return match