* @extends Ext.form.field.Trigger
* <p>A field with a pair of up/down spinner buttons. This class is not normally instantiated directly,
* instead it is subclassed and the {@link #onSpinUp} and {@link #onSpinDown} methods are implemented
* @extends Ext.form.field.Trigger
* <p>A field with a pair of up/down spinner buttons. This class is not normally instantiated directly,
* instead it is subclassed and the {@link #onSpinUp} and {@link #onSpinDown} methods are implemented