numeric method Null safety
Implementation
static String? numeric(String? value, {String? message}) =>
value == null || value.isEmpty || validations.isNumeric(value) ? null : message ?? 'Please enter a valid number';
static String? numeric(String? value, {String? message}) =>
value == null || value.isEmpty || validations.isNumeric(value) ? null : message ?? 'Please enter a valid number';