This example demonstrates two reusable legend components in D3 v5: a color legend for ordinal scales and a size legend for quantitative scales. The color legend maps fruit names to distinct colors using `scaleOrdinal`, while the size legend uses `scaleSqrt` to represent numeric ticks as proportional circle radii. Both legends are rendered as SVG groups with circles and text, using `.call()` to apply the component functions. The size legend filters out zero values and reverses tick order to display larger circles first.