code: def test_cumsum(self, unit):
      # GH#50297
      dtype = f"m8[{unit}]"
      arr = TimedeltaArray._from_sequence(["1D", "2D"], dtype=dtype)
      result = arr._accumulate("cumsum")
      expected = TimedeltaArray._from_sequence(
          ["1D", "3D"], dtype=dtype
      )
      tm.assert_timedelta_array_equal(result, expected)
  
imports: import pytest
  import pandas._testing
  from pandas.core.arrays import TimedeltaArray
label_desc: Use image node_id 2 for calling the TestAccumulator obj's underlying member method code with example usage: obj.test_cumsum(unit) without return types