How to use the cjio.validation function in cjio

#-- 3. extraAttributes
            if "extraAttributes" in js:
                for thetype in js["extraAttributes"]:
                    for ea in js["extraAttributes"][thetype]:
                        jtmp = {}
                        jtmp["$schema"] = "http://json-schema.org/draft-07/schema#"
                        jtmp["type"] = "object"
                        jtmp["$ref"] = "file://%s#/extraAttributes/%s/%s" % (schemapath, thetype, ea)
                        jsotf = jsonref.loads(json.dumps(jtmp), jsonschema=True, base_uri=base_uri)
                        for theid in self.j["CityObjects"]:
                            if ( (self.j["CityObjects"][theid]["type"] == thetype) and 
                                 ("attributes" in self.j["CityObjects"][theid])    and
                                 (ea in self.j["CityObjects"][theid]["attributes"]) ):
                                a = self.j["CityObjects"][theid]["attributes"][ea]
                                v, errs = validation.validate_against_schema(a, jsotf)
                                if (v == False):
                                    isValid = False
                                    es += errs


        #-- 4. check if there are CityObjects that do not have a schema
        for theid in self.j["CityObjects"]:
            if ( (self.j["CityObjects"][theid]["type"][0] == "+") and
                 (self.j["CityObjects"][theid]["type"] not in allnewco) ):
                s = "ERROR:   CityObject " + self.j["CityObjects"][theid]["type"] + " doesn't have a schema."
                es.append(s)
                isValid = False

        return (isValid, es)

if (v == False):
                                isValid = False
                                es += errs

            #-- 2. extraRootProperties
            if "extraRootProperties" in js:
                for nrp in js["extraRootProperties"]:
                    jtmp = {}
                    jtmp["$schema"] = "http://json-schema.org/draft-07/schema#"
                    jtmp["type"] = "object"
                    jtmp["$ref"] = "file://%s#/extraRootProperties/%s" % (schemapath, nrp)
                    jsotf = jsonref.loads(json.dumps(jtmp), jsonschema=True, base_uri=base_uri)
                    for p in self.j:
                        if p == nrp:
                            thep = self.j[p]
                            v, errs = validation.validate_against_schema(thep, jsotf)
                            if (v == False):
                                isValid = False
                                es += errs

            #-- 3. extraAttributes
            if "extraAttributes" in js:
                for thetype in js["extraAttributes"]:
                    for ea in js["extraAttributes"][thetype]:
                        jtmp = {}
                        jtmp["$schema"] = "http://json-schema.org/draft-07/schema#"
                        jtmp["type"] = "object"
                        jtmp["$ref"] = "file://%s#/extraAttributes/%s/%s" % (schemapath, thetype, ea)
                        jsotf = jsonref.loads(json.dumps(jtmp), jsonschema=True, base_uri=base_uri)
                        for theid in self.j["CityObjects"]:
                            if ( (self.j["CityObjects"][theid]["type"] == thetype) and 
                                 ("attributes" in self.j["CityObjects"][theid])    and

def read(self, file, ignore_duplicate_keys=False):
        if ignore_duplicate_keys == True:
            self.j = json.loads(file.read())
        else:
            try:
                self.j = json.loads(file.read(), object_pairs_hook=validation.dict_raise_on_duplicates)
            except ValueError as err:
                raise ValueError(err)
        #-- a CityJSON file?
        if "type" in self.j and self.j["type"] == "CityJSON":
            pass
        else:
            self.j = {}
            raise ValueError("Not a CityJSON file")