public static boolean isValid(final GitReference ref) {
        if (ref == null) {
            return false;
        }

        String name = ref.ref();
        return !TextUtils.isEmpty(name) && !name.startsWith(PREFIX_PULL);
    }
Should the given reference be included as valid?
<p>
This filters out pull request refs

@param ref
@return true if valid, false otherwise
app/src/main/java/com/github/pockethub/android/core/ref/RefUtils.java