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Detach detailed implementation to member function.
Put implementation member functions in order.
Create a 'TileCollection' class to orginize 'Tile's.
Create new files and assign each class to each file.
Add 'Edge' class
Modified order of events.
Better variable name
Modify functions to put a tile
Save information of edges of tiles.
Improve performance and readability
Improve rotation implementation
Improve readability
Implement functions about adhesion
Improve readability
Better identifier name
Better order of declaration
Implement functions to calculate distance between edges.
Enhance assert check
Add 'const' to local variables.