package org.grouplens.reflens.util;

public interface DoubleFunction {
	double apply(double v);
	
	public static class Identity implements DoubleFunction {
		public double apply(double v) {
			return v;
		}
	}
}

@@ -106,16 +106,22 @@
  static 
+final 
 class Id

Make Identity double function final.