使用poco获取控件，点击报错poco.utils.simplerpc.simplerpc.RpcTimeoutError

**代码如下：**
# -*- encoding=utf8 -*-
__author__ = "Administrator"

from airtest.core.api import *

auto_setup(__file__)

from poco.drivers.unity3d import UnityPoco
poco = UnityPoco()

poco("Btn_Play").click()

**报错信息如下**：
ERROR: runTest (__main__.CustomCase)
----------------------------------------------------------------------
Traceback (most recent call last):
File "C:\Users\Administrator.FUN-20180413JLM\AppData\Local\Programs\Python\Python37\lib\site-packages\airtest\cli\runner.py", line 65, in runTest
six.reraise(*sys.exc_info())
File "C:\Users\Administrator.FUN-20180413JLM\AppData\Local\Programs\Python\Python37\lib\site-packages\six.py", line 693, in reraise
raise value
File "C:\Users\Administrator.FUN-20180413JLM\AppData\Local\Programs\Python\Python37\lib\site-packages\airtest\cli\runner.py", line 61, in runTest
exec(compile(code.encode("utf-8"), pyfilepath, 'exec'), self.scope)
File "E:\happyword\HappyWordTest\cases\untitled.air\untitled.py", line 11, in
poco("Btn_Play").click()
File "C:\Users\Administrator.FUN-20180413JLM\AppData\Local\Programs\Python\Python37\lib\site-packages\poco\proxy.py", line 23, in wrapped
return func(proxy, *args, **kwargs)
File "C:\Users\Administrator.FUN-20180413JLM\AppData\Local\Programs\Python\Python37\lib\site-packages\poco\proxy.py", line 332, in click
pos_in_percentage = self.get_position(focus)
File "C:\Users\Administrator.FUN-20180413JLM\AppData\Local\Programs\Python\Python37\lib\site-packages\poco\proxy.py", line 72, in wrapped
return func(proxy, *args, **kwargs)
File "C:\Users\Administrator.FUN-20180413JLM\AppData\Local\Programs\Python\Python37\lib\site-packages\poco\proxy.py", line 613, in get_position
pos = self.attr('pos')
File "C:\Users\Administrator.FUN-20180413JLM\AppData\Local\Programs\Python\Python37\lib\site-packages\poco\proxy.py", line 39, in wrapped
return func(self, *args, **kwargs)
File "C:\Users\Administrator.FUN-20180413JLM\AppData\Local\Programs\Python\Python37\lib\site-packages\poco\proxy.py", line 734, in attr
nodes = self._do_query(multiple=False)
File "C:\Users\Administrator.FUN-20180413JLM\AppData\Local\Programs\Python\Python37\lib\site-packages\poco\proxy.py", line 872, in _do_query
self._nodes = self.poco.agent.hierarchy.select(self.query, multiple)
File "C:\Users\Administrator.FUN-20180413JLM\AppData\Local\Programs\Python\Python37\lib\site-packages\poco\freezeui\hierarchy.py", line 90, in select
return self.selector.select(query, multiple)
File "C:\Users\Administrator.FUN-20180413JLM\AppData\Local\Programs\Python\Python37\lib\site-packages\poco\sdk\Selector.py", line 78, in select
return self.selectImpl(cond, multiple, self.getRoot(), 9999, True, True)
File "C:\Users\Administrator.FUN-20180413JLM\AppData\Local\Programs\Python\Python37\lib\site-packages\poco\sdk\Selector.py", line 71, in getRoot
return self.dumper.getRoot()
File "C:\Users\Administrator.FUN-20180413JLM\AppData\Local\Programs\Python\Python37\lib\site-packages\poco\freezeui\hierarchy.py", line 35, in getRoot
root = Node(self.dumpHierarchy())
File "C:\Users\Administrator.FUN-20180413JLM\AppData\Local\Programs\Python\Python37\lib\site-packages\poco\utils\simplerpc\utils.py", line 13, in new_func
ret, err = cb.wait(timeout=30)
File "C:\Users\Administrator.FUN-20180413JLM\AppData\Local\Programs\Python\Python37\lib\site-packages\poco\utils\simplerpc\simplerpc.py", line 78, in wait
raise RpcTimeoutError(self)
poco.utils.simplerpc.simplerpc.RpcTimeoutError: (rid=c375504e-08f0-45b4-b01b-a402fbe75779) (connection="tcp://127.0.0.1:14234")

----------------------------------------------------------------------
Ran 1 test in 30.388s

FAILED (errors=1)
[11:54:22][DEBUG] C:\Users\Administrator.FUN-20180413JLM\AppData\Local\Programs\Python\Python37\lib\site-packages\airtest\core\android\static\adb\windows\adb.exe -P 5037 -s 127.0.0.1:7555 forward --remove tcp:14234
[Finished]

**设备：**
mumu模拟器2.2.12（X86）

python版本：
3.7