Type.actualArgumentTypes aren't resolved when field declared with wildcard generic

public void testFieldWithWildcardType()
    {
       JavaDocBuilder javaDocBuilder = new JavaDocBuilder();
       StringBuilder b = new StringBuilder("package test;\n");
       b.append("import java.util.ArrayList;\n");
       b.append("import java.util.Map;\n");
       b.append("public class TestClass<E>{\n");
       b.append("public ArrayList<? extends Map<String, E>> list;\n}");
       javaDocBuilder.addSource(new StringReader(b.toString()));
       JavaClass javaClass = javaDocBuilder.getClasses()[0];
       JavaField field = javaClass.getFields()[0];
       assertNotNull(field.getType().getActualTypeArguments()[0].getActualTypeArguments());
       assertEquals("? extends java.util.Map<java.lang.String,E>", field.getType().getActualTypeArguments()[0].getGenericValue());
    }

this.actualArgumentTypes = typeDef.actualArgumentTypes;