code: function decodeTag(s, tag) {
  	var nextTag = new type.UInt8().read(s).value;
  	if (tag.tagNumber > 30) {
  		nextTagNumber = new type.UInt8().read(s).value;
  	}
  	else {
  		nextTagNumber = nextTag & 0x1F;
  	}
  	
  	return ((nextTag & 0xE0) === (tag.tagClass | tag.tagFormat)) && (nextTagNumber === tag.tagNumber);
  }
docs: Parse tag(T) field of BER TLV
  And check with expected tag
  @param s {type.Stream}
  @param tag {spec.tag}
  @returns {Boolean} True for valid tag matching