private void sendErrorResponseForCall(int id, long totalRequestSize, Span span, String msg,
    Throwable responseThrowable) throws IOException {
    ServerCall<?> failedcall = createCall(id, this.service, null, null, null, null,
      totalRequestSize, null, 0, this.callCleanup);
    failedcall.setResponse(null, null, responseThrowable, msg);
    TraceUtil.setError(span, responseThrowable);
    failedcall.sendResponseIfReady();
  }
Has the request header and the request param and optionally encoded data buffer all in this one
array.
<p/>
Will be overridden in tests.
hbase-server/src/main/java/org/apache/hadoop/hbase/ipc/ServerRpcConnection.java