Tetris Game Design

Design and implement a simplified, console-style Tetris game. Your task is to write a class (or set of classes) that models an endless Tetris session. The board is a fixed 10×20 grid (width × height) implemented as a 2-D array of booleans/integers. Seven tetrominoes (I, O, T, S, Z, J, L) must be supported; each piece spawns at the top centre with a random rotation. The public API must expose exactly one key method:

int drop(int pieceType, int rotation, int column)

• pieceType ∈ [0,6] maps to the seven tetrominoes.
• rotation ∈ [0,3] is the number of 90° clockwise turns applied to the piece’s base template.
• column ∈ [0,9] is the left-most board column the piece’s bounding box occupies when it first appears.

The method must:

1. Instantiate the requested tetromino, rotate it, and place it so its top-left corner is at (column, 0).
2. Simulate gravity: move the piece down row-by-row until it collides with the floor or an already locked block.
3. Lock the piece in place.
4. Clear every full row (all 10 cells occupied) and shift every row above down by the number of cleared rows.
5. Return the exact count of rows that were cleared during this single drop.

No user input, scoring, line-count multipliers, or next-piece queue are required; focus purely on the core drop-and-clear mechanics. State must persist across calls so successive drops accumulate locked blocks and the board evolves accordingly.