### Question:
ItemParamPriorBeta4 implements ItemParamPrior { public double logDensity(double p){ if (zeroDensity(p)){ return Double.MIN_VALUE; } double value = (parameters[0] - 1.0) * Math.log(p - parameters[2]); value += (parameters[1] - 1.0) * Math.log(parameters[3] - p); return value; } ItemParamPriorBeta4();  ItemParamPriorBeta4(double a, double b, double l, double u); double nearestNonZero(double x); boolean zeroDensity(double p); double logDensity(double p); double logDensityDeriv1(double p); double logDensityDeriv2(double p); int getNumberOfParameters(); String distributionName();  }### Answer:
@Test public void testDistribution(){ ItemParamPrior beta4 = new ItemParamPriorBeta4(1, 4, 0, 0.8); UniformQuadratureRule dist = new UniformQuadratureRule(-1.5, 1.5, 50); System.out.println(beta4.logDensity(0.442053)); }