private void addBytes(byte functionStateOrHasResult) {
      if (getTimeoutMs() == DEFAULT_CLIENT_FUNCTION_TIMEOUT) {
        getMessage().addBytesPart(new byte[] {functionStateOrHasResult});
      } else {
        byte[] bytes = new byte[5];
        bytes[0] = functionStateOrHasResult;
        Part.encodeInt(getTimeoutMs(), bytes, 1);
        getMessage().addBytesPart(bytes);
      }
    }
Does a execute Function on a server using connections from the given pool to communicate with
the server.
geode-core/src/main/java/org/apache/geode/cache/client/internal/ExecuteRegionFunctionOp.java