docstr: Test the scalar's cov factor for an empty array.
docstr_tok: ["Test","the","scalar","'s","cov","factor","for","an","empty","array","."]
code: def test_scalar_empty_dataset(self):
      """Test the scalar's cov factor for an empty array."""
      with pytest.raises(ValueError):
          mlab.GaussianKDE([], bw_method=5)
  
imports: from numpy.testing import assert_allclose, assert_almost_equal, assert_array_equal, assert_array_almost_equal_nulp
  import numpy
  import pytest
  from matplotlib import mlab
label_desc: Use image node_id 7 for calling the TestGaussianKDECustom obj's underlying member method code with example usage: obj.test_scalar_empty_dataset() without return types