This is the lodash codebase, a modern JavaScript utility library delivering modularity, performance, and extras built with ES modules and TypeScript support.
Your task is to add TypeScript generics and type guards to enforce numeric return types on all numeric aggregation functions (sum, sumBy, mean, meanBy, min, minBy, max, maxBy).
Requirements:
- Create a type guard function
isNumericthat validates if a value can be safely used in numeric operations - Add TypeScript generic constraints to ensure iteratee functions return number | undefined | null