code: def non_fixed_freqs(self):
      return ["W", "Q"]
  
imports: import pandas
  import pyspark.pandas
  from pyspark.testing.pandasutils import PandasOnSparkTestCase, TestUtils
label_desc: Use image node_id 2 for calling the DatetimeIndexTestingFuncMixin obj's underlying member method code with example usage: obj.non_fixed_freqs() and returns: list