code: def test_set_mask(self):
      base = self.base.copy()
      mbase = base.view(mrecarray)
      # Set the mask to True .......................
      mbase.mask = masked
      assert_equal(ma.getmaskarray(mbase["b"]), [1] * 5)
      assert_equal(mbase["a"]._mask, mbase["b"]._mask)
      assert_equal(mbase["a"]._mask, mbase["c"]._mask)
      assert_equal(
          mbase._mask.tolist(), np.array([(1, 1, 1)] * 5, dtype=bool)
      )
      # Delete the mask ............................
      mbase.mask = nomask
      assert_equal(ma.getmaskarray(mbase["c"]), [0] * 5)
      assert_equal(
          mbase._mask.tolist(), np.array([(0, 0, 0)] * 5, dtype=bool)
      )
  
imports: import pickle
  import numpy
  import numpy.ma
  from numpy.ma import masked, nomask
  from numpy.testing import temppath
  from numpy._core.records import recarray, fromrecords, fromarrays
  from numpy.ma.mrecords import MaskedRecords, mrecarray, fromarrays, fromtextfile, fromrecords, addfield
  from numpy.ma.testutils import assert_, assert_equal, assert_equal_records
label_desc: Use image node_id 5 for calling the TestMRecords obj's underlying member method code with example usage: obj.test_set_mask() without return types