This example demonstrates the general update pattern for enter, update, and exit selections in D3. Circles representing apples and lemons enter with zero radius, transition to their target size, and exit by shrinking to nothing. State changes include removing fruit, replacing an apple with a lemon, and filtering, all triggered by `setTimeout`. The visualization uses `d3.selectAll`, `.data()` with an id key, `.enter()`, `.merge()`, `.exit()`, and `.remove()` along with `transition().duration()`. Colors and radii come from `scaleOrdinal` ranges.