code: def _has_upward_trend(arr):
      from scipy.stats import spearmanr
  
      corr = spearmanr(range(len(arr)), arr)
      return corr[0] > 0 and corr[1] < 0.1
  
file_path: nni/test/algo/nas/strategy/test_rl_impl.py
imports: from functools import partial
  import numpy
  import pytest
  from tianshou.data import ReplayBuffer, Batch
  from tianshou.policy import BasePolicy
  from nni.mutable import Categorical, Numerical, CategoricalMultiple, MutableDict, MutableList, ExpressionConstraint
  from nni.nas.strategy._rl_impl import TuningTrajectoryGenerator, default_policy_fn
label_desc: Use image node_id 1 for calling a global function with example usage: _has_upward_trend(arr) and returns: unknown