code: public static Long convertToLong(RLPElement rpe) {
  	Long result=0L;
  	byte[] rawBytes=rpe.getRawData();
  	if ((rawBytes!=null)) {
  			// fill leading zeros
  			if (rawBytes.length<EthereumUtil.LONG_SIZE) {
  				byte[] fullBytes=new byte[EthereumUtil.LONG_SIZE];
  				int dtDiff=EthereumUtil.LONG_SIZE-rawBytes.length;
  				for (int i=0;i<rawBytes.length;i++) {
  					fullBytes[dtDiff+i]=rawBytes[i];
  					result=ByteBuffer.wrap(fullBytes).getLong();
  				}
  			} else {
  				result=ByteBuffer.wrap(rawBytes).getLong();
  			}
  	}
  	return result;
  }
docs: Converts a long in a RLPElement to long
  
  @param rpe RLP element containing a raw long
  @return long or null if not long