You're working with a class that has multiple constructors. During code review, you were asked to refactor them using initialization lists for better performance and cleaner code.

• The default constructor should delegate to the main constructor, passing default values.
• The constructor that sets only the name should also delegate, using defaults for the other fields.
• The one that sets name and age should delegate too, passing a default salary.
• The fully parameterized constructor stays as is.