code: def test_raster_range_masked(self):
      arr = np.random.rand(10, 10) - 0.5
      arr = np.ma.masked_where(arr <= 0, arr)
      rrange = Raster(arr).range(2)
      self.assertEqual(rrange, (np.min(arr), np.max(arr)))
  
imports: import numpy
  from holoviews.element import HSV, RGB, Curve, Image, QuadMesh, Raster
  from holoviews.element.comparison import ComparisonTestCase
label_desc: Use image node_id 5 for calling the TestRaster obj's underlying member method code with example usage: obj.test_raster_range_masked() without return types