• As the user scrolls, rows that are no longer visible will be freed, and new rows that become visible will be allocated.
• In order to recycle rows properly, we must always be aware of the current scroll offset since rows must be recycled as soon as the user scrolls.
• Every contact row probably looks the same and has the same structure.
• If your use-case falls under the second use-case: High variation between rows and a smaller data-source — you should probably stick with the stock ListView implementation.
• If a cell can be recycled (from a row gone off-screen), this method will return the recycled cell.

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