self = <test_golang.Test testMethod=test_stats>

    def test_stats(self):
        """
        golang heap test
        """
        self.render_config_template(modules=[{
            "name": "golang",
            "metricsets": ["heap"],
            "hosts": ["http://localhost:6060"],
            "period": "1s"
        }])
        proc = self.start_beat(
            extra_args=["-httpprof", "localhost:6060"])
    
>       self.wait_until(lambda: self.output_lines() > 0)

module\golang\test_golang.py:25: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <test_golang.Test testMethod=test_stats>
cond = <function Test.test_stats.<locals>.<lambda> at 0x000001A155CE9700>
max_timeout = 10, poll_interval = 0.1, name = 'cond'

    def wait_until(self, cond, max_timeout=10, poll_interval=0.1, name="cond"):
        """
        Waits until the cond function returns true,
        or until the max_timeout is reached. Calls the cond
        function every poll_interval seconds.
    
        If the max_timeout is reached before cond() returns
        true, an exception is raised.
        """
        start = datetime.now()
        while not cond():
            if datetime.now() - start > timedelta(seconds=max_timeout):
>               raise TimeoutError("Timeout waiting for '{}' to be true. ".format(name) +
                                   "Waited {} seconds.".format(max_timeout))
E               beat.beat.TimeoutError: Timeout waiting for 'cond' to be true. Waited 10 seconds.

..\libbeat\tests\system\beat\beat.py:362: TimeoutError