Instruction: Explain what decorators are in TypeScript and provide a use case example.
Context: This question evaluates the candidate's knowledge of decorators in TypeScript and their ability to describe how decorators provide a way to add annotations and a meta-programming syntax for class declarations and members.
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At their core, decorators are special kinds of declarations that can be attached to a class declaration, method, accessor, property, or parameter. Decorators use the form @expression, where the expression must evaluate to a function that will be called at runtime with information about the decorated declaration.
To give you a concrete example, one common use case for decorators is logging. Imagine we're working on a large-scale application where tracking method executions and their runtimes is crucial for performance monitoring. We could define a Log decorator that wraps any method and logs its execution time. Here's a simplified version of what...
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