Each attribute is mutually exclusive, so only set one attribute per annotation instance
(the one most convenient one for your formatting needs). When the pattern attribute is specified,
it takes precedence over the style attribute. When no annotation attributes are specified,
the default format applied is style-based with a style of
public abstract NumberFormat.Style style
NumberFormat.Style.NUMBER for general-purpose number formatter.
Set this attribute when you wish to format your field in accordance with a
common style other than the default style.
public abstract String pattern
Defaults to empty String, indicating no custom pattern String has been specified. Set this attribute when you wish to format your field in accordance with a custom number pattern not represented by a style.