The _________ package is widely used for dependency injection in complex Flutter applications.

The 'get_it' package is widely used for dependency injection in complex Flutter applications. Dependency injection is a crucial technique for managing the dependencies of various components in an app. 'get_it' provides a simple and flexible service locator that allows developers to register and retrieve instances of their classes. It is especially valuable in scenarios where multiple classes or widgets need to access shared dependencies. Understanding how to use 'get_it' is essential for building scalable and maintainable Flutter applications.