private static boolean tryEncoding(byte[] sig, byte b1, byte b2) {
        return ((sig[0] == b1) && (sig[1] == b2));
    }
Check for a two-byte signature.
<p>
Looks for a UCS-2 byte-order mark.
<p>
Utility routine for detectEncoding ().

@param sig
           The first four bytes read.
@param b1
           The first byte of the signature
@param b2
           The second byte of the signature
@see #detectEncoding
src/nu/validator/gnu/xml/aelfred2/XmlParser.java