Nested-List Iterator

Implement a Python iterator over an array of integer arrays with `hasNext()`, `next()`, and `remove()`. Traversal is row-major, and `remove()` must delete the last returned value from the original nested list without causing the following value to be skipped. Requirements Implement a Python iterator class over a nested list of integers. Traverse each inner list from left to right and the outer list from top to bottom. Support three methods: hasNext() returns whether another integer exists after the current cursor. next() returns the next integer in traversal order. remove() deletes the last value returned by next() from the original nested-list object. Skip empty inner lists. Allow hasNext() to be called repeatedly without advancing the iterator. Allow remove() at most once after each successful next(). Raise an exception when remove() is called before next(), when it is called twice for the same returned element, or when next() is called after exhaustion. After a removal, preserve the cursor so the next element in the same inner list is not skipped. Examples Starting data: [[], [1, 2, 3], [4, 5], [], [], [6], [7, 8], [], [9], [10], []] If next() returns 2 from: [[], [1, 2, 3], [4, 5]] then remove() must mutate the original data to: [[], [1, 3], [4, 5]] The following next() call must return 3. Notes Removal mutates the object supplied to the iterator; it is not a detached traversal view. The state must distinguish the cursor for the next candidate from the position of the last returned value. Deleting an element before the current cursor in the same row shifts the remaining indices and must not skip the successor. Preparation Implement the iterator against the full nested-list example and verify row transitions across consecutive empty lists. Write unit tests for repeated hasNext(), removal before the first next(), double removal, removal of the final item in a row, and calls after exhaustion. Practice explaining the iterator state and every cursor update before coding.