@Override
    default boolean isNullable() {
        return nullableProperty().get();
    }
Returns a property that holds a value showing if the column can contain
{@code NULL} values. This property should only be edited when and if the
database has been modified.

@return  a {@code BooleanProperty} of the 
         {@link HasNullable#isNullable()}-state of this column
tool-parent/tool-config/src/main/java/com/speedment/tool/config/trait/HasNullableProperty.java