docs: public static int munmap(Pointer addr, long len) throws IOException {
  
          int result = Delegate.munmap(addr, new NativeLong(len));
  
          if(result != 0) {
              if(logger.isDebugEnabled())
                  logger.debug(errno.strerror());
  	    throw new IOException("munmap failed: " + errno.strerror());
          }
  
          return result;
  
      }