### Question:
Linear extends TransferFunction implements Serializable { @Override public double getDerivative(double net) { return this.slope; } Linear();  Linear(double slope);  Linear(NeurophProperties properties); double getSlope(); void setSlope(double slope); @Override double getOutput(double net); @Override double getDerivative(double net);  }### Answer:
@Test public void testgetDerivative() { double result = instance.getDerivative(input); assertEquals(1, result, 0.0); }
@Test public void testgetDerivativewthproperties() { NeurophProperties properties = new NeurophProperties(); properties.setProperty("transferFunction.slope", 1.0); instance = new Linear(properties); double result = instance.getDerivative(input); assertEquals(1, result, 0.0); }