Fix to Issue #33 - pushing the verbose ImmutableBy...

src/test/benchmarks/org/mutabilitydetector/benchmarks/ImmutableByHavingOnlyAPrivateConstructorUsingTheBuilderPattern.java

@@ -1,5 +1,25 @@
 package org.mutabilitydetector.benchmarks;
-
+ 
 public class ImmutableByHavingOnlyAPrivateConstructorUsingTheBuilderPattern {
-
-}
+  private final String field;
+
+	// usual method of making a class immutable 
+	// - make its constructor private: ref EffectiveJava
+	private ImmutableByHavingOnlyAPrivateConstructorUsingTheBuilderPattern (String field) {
+		this.field = field;
+	}
+
+	public String getField() {
+		return field;
+	}
+
+	// inner Builder class
+	public static class Builder {
+		public ImmutableByHavingOnlyAPrivateConstructorUsingTheBuilderPattern build() {
+			// this new OnlyPrivateConstructors() is fooling mutability detector
+			// it thinks OnlyPrivateConstructors() is no longer immutable due to the
+			// ability to call new to create an instance of OnlyPrivateConstructors.
+			return new ImmutableByHavingOnlyAPrivateConstructorUsingTheBuilderPattern("hi");
+		}
+	}
+}