pushUnique abstract method

Future<void> pushUnique(
  1. String key,
  2. String value
)

Create array property, if property does not exist and add value to array, only if value is not yet in the array You can only use it on array properties or properties that do not exist yet String key - property name for array property String value - value to add to array

Implementation

Future<void> pushUnique(String key, String value);