This example demonstrates two custom legend components built with D3 v5: a color legend using an ordinal scale for categorical data (apple, lemon, lime, orange) and a size legend using a square-root scale for continuous numeric values. The color legend renders colored circles with text labels, while the size legend generates circles whose radii correspond to tick values, filtering out zero. Both legends are implemented as reusable functions that append SVG groups, using `scaleOrdinal` and `scaleSqrt` to map data domains to visual properties, with spacing and text offsets controlled by configuration props.