maxProperties: function (report, schema) {
        // http://json-schema.org/latest/json-schema-validation.html#rfc.section.5.4.1.1
        if (Utils.whatIs(schema.maxProperties) !== "integer") {
            report.addError("KEYWORD_TYPE_EXPECTED", ["maxProperties", "integer"]);
        } else if (schema.maxProperties < 0) {