### Question:
LaguerrePolynomialFunction extends OrthogonalPolynomialFunctionGenerator { @Override public Pair<DoubleFunction1D, DoubleFunction1D>[] getPolynomialsAndFirstDerivative(int n) { return getPolynomialsAndFirstDerivative(n, 0); }  @Override DoubleFunction1D[] getPolynomials(int n); @Override Pair<DoubleFunction1D, DoubleFunction1D>[] getPolynomialsAndFirstDerivative(int n); DoubleFunction1D[] getPolynomials(int n, double alpha); Pair<DoubleFunction1D, DoubleFunction1D>[] getPolynomialsAndFirstDerivative(int n, double alpha);  }### Answer:
@Test public void testAlpha2() { final int n = 14; final Pair<DoubleFunction1D, DoubleFunction1D>[] polynomialAndDerivative1 = LAGUERRE.getPolynomialsAndFirstDerivative(n); final Pair<DoubleFunction1D, DoubleFunction1D>[] polynomialAndDerivative2 = LAGUERRE.getPolynomialsAndFirstDerivative(n, 0); for (int i = 0; i < n; i++) { assertThat(polynomialAndDerivative1[i].getFirst() instanceof RealPolynomialFunction1D).isTrue(); assertThat(polynomialAndDerivative2[i].getFirst() instanceof RealPolynomialFunction1D).isTrue(); final RealPolynomialFunction1D first = (RealPolynomialFunction1D) polynomialAndDerivative1[i].getFirst(); final RealPolynomialFunction1D second = (RealPolynomialFunction1D) polynomialAndDerivative2[i].getFirst(); assertThat(first).isEqualTo(second); } }