getValue<T> abstract method
Method to get custom object value from the storage, if the retrieved value is null
then defaultValue
should be used, if provided.
Example code(SharedPreferences Implementation): /// ```dart T? getValue
T - Represents any valid class or primitive types supported by flutter
The [defaultValue] is an optional & nullable value, you may choose not to provide it
in which case the null value will be returned as result.
Output can be represented like this:
getterOutput -if-absent-> defaultValue -if-absent-> null
here [getterOutput] is the expected output of the getter method called.
The method must be implementation of one of the definitions from the cache provider
Implementation
T? getValue<T>(String key, {T? defaultValue});