### Question:
VariableSampleSource implements SampleSource { @Override public int getWidth() { return width; } VariableSampleSource(Variable variable, Array slice); @Override int getWidth(); @Override int getHeight(); @Override double getSample(int x, int y); @Override boolean isFillValue(int x, int y);  }### Answer:
@Test public void testGetWidth() { final int width = sampleSource.getWidth(); assertEquals(WIDTH, width); }