code: def _test_merge_empty(self, fn):
      left = self.data1.toPandas()
      right = self.data2.toPandas()
  
      expected = pd.merge(
          left[left["id"] % 2 != 0],
          right[right["id"] % 3 != 0],
          on=["id", "k"],
      ).sort_values(by=["id", "k"])
  
      self._test_merge(self.data1, self.data2, fn=fn, expected=expected)
  
imports: import unittest
  from typing import cast
  from pyspark.sql.functions import array, explode, col, lit, udf, pandas_udf, sum
  from pyspark.sql.types import ArrayType, DoubleType, LongType, StructType, StructField, YearMonthIntervalType, Row
  from pyspark.sql.window import Window
  from pyspark.errors import IllegalArgumentException, PythonException
  from pyspark.testing.sqlutils import ReusedSQLTestCase, have_pandas, have_pyarrow, pandas_requirement_message, pyarrow_requirement_message
  from pyspark.testing.utils import QuietTest
label_desc: Use image node_id 39 for calling the CogroupedApplyInPandasTestsMixin obj's underlying member method code with example usage: obj._test_merge_empty(fn) without return types