What this snippet does
Mixins compose behavior by wrapping base classes — avoids deep inheritance chains while sharing logic across classes.
Expected output
{"name":"Alice","age":30,"createdAt":"..."}
2024-01-01T00:00:00.000ZWhy practise typing this
Typing classes code builds muscle memory for the symbols and indentation JavaScript uses most, which prose-based typing tests never cover. DevType measures your words per minute and accuracy on this snippet and tracks the individual characters you mistype, so later lessons can target them.
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