fields() public method
Returns the list of fields that should be returned by default by toArray() when no specific fields are specified. A field is a named element in the returned array by toArray(). This method should return an array of field names or field definitions. If the former, the field name will be treated as an object property name whose value will be used as the field value. If the latter, the array key should be the field name while the array value should be the corresponding f