setParent abstract method

Sets the parent of this application context.

Establishes a parent-child relationship where this context becomes the child and inherits configuration and pods from the parent.

Parent-Child Semantics:

• Configuration Inheritance: Child inherits parent's environment setup
• Pod Delegation: Child can access pods from parent context
• Lifecycle Independence: Child lifecycle independent from parent
• Event Isolation: Events not propagated between parent and child

Usage:

// Create parent context with shared services
final parentContext = GenericApplicationContext();
parentContext.registerSingleton('dataSource', DataSource());
parentContext.registerSingleton('configService', ConfigService());
await parentContext.refresh();

// Create child context with module-specific services
final childContext = GenericApplicationContext();
childContext.setParent(parentContext);
childContext.registerSingleton('userService', UserService());
await childContext.refresh();

// Child can access both its own and parent's pods
final userService = childContext.getPod<UserService>(); // From child
final dataSource = childContext.getPod<DataSource>();   // From parent

Important:

Parent must be set before context refresh and cannot be changed afterward.