Add convenience method that is easire to grok

Author: jeffgbutler

src/main/java/org/mybatis/dynamic/sql/AbstractListValueCondition.java

@@ -44,6 +44,13 @@ public boolean skipRenderingWhenEmpty() {
         return skipRenderingWhenEmpty;
     }
 
+    /**
+     * Use with caution - this could cause the library to render invalid SQL like "where column in ()".
+     */
+    protected void forceRenderingWhenEmpty() {
+        skipRenderingWhenEmpty = false;
+    }
+    
     @Override
     public <R> R accept(ConditionVisitor<T, R> visitor) {
         return visitor.visit(this);

src/test/java/examples/animal/data/AnimalDataTest.java

@@ -589,7 +589,7 @@ void testInConditionWithEmptyList() {
     public static class IsInRequired<T> extends IsIn<T> {
         protected IsInRequired(Collection<T> values) {
             super(values);
-            skipRenderingWhenEmpty = false;
+            forceRenderingWhenEmpty();
         }
 
         public static <T> IsInRequired<T> isIn(Collection<T> values) {