@kimchy seems check the second byte won't success
I've created a gist to test that with first field string, number and boolean, non of them would return `MatchStrength.SOLID_MATCH`, it always return `MatchStrength.INCONCLUSIVE`

And look at their test case https://github.com/FasterXML/jackson-dataformat-cbor/blob/master/src/test/java/com/fasterxml/jackson/dataformat/cbor/GeneratorSimpleTest.java#L238
Seems the second byte should be `CBORConstants.PREFIX_TYPE_TEXT + size of the field name`, and that works fine.

How about change the check to 
```java
if (length > 1 && first == CBORConstants.BYTE_OBJECT_INDEFINITE && (bytes.get(1) & CBORConstants.PREFIX_TYPE_TEXT) == CBORConstants.PREFIX_TYPE_TEXT){
            return XContentType.CBOR;
        }
```



https://gist.github.com/kzwang/9751129