This example demonstrates two custom legend components built with D3 v5 and rendered as SVG. A color legend uses `scaleOrdinal` to map fruit categories to distinct circle fills, while a size legend employs `scaleSqrt` with `ticks()` to encode numeric values as varying circle radii. Both legends bind data to grouped `<g>` elements, applying enter/merge/exit selections for dynamic updates. The code defines reusable functions `colorLegend` and `sizeLegend`, called via `.call()`, with text labels positioned using `textOffset`.