StableValue<T> is not part of the Java Standard Library but represents a design pattern or custom utility used to capture and work with values that do not change once initialized—often as a wrapper to enforce immutability and predictability in code.

• When you want to explicitly express that a value, once set, should not change.
• Useful for configuration values, shared constants, or lazy-initialized but stable results.
• Can be implemented as a final wrapper class or a record in Java.

public final class StableValue<T> {
    private final T value;

    public StableValue(T value) {
        this.value = value;
    }

    public T get() {
        return value;
    }
}

// Usage
StableValue<String> apiKey = new StableValue<>("ABC123");
System.out.println(apiKey.get());  // "ABC123"

Or using record (Java 16+):

public record StableValue<T>(T value) { }

// Usage
StableValue<Integer> maxConnections = new StableValue<>(10);
System.out.println(maxConnections.value()); // 10

This utility encourages safer design by limiting change and clarifying intent in your code.