add owerloaded isDraw() without arguments
add stats interface
field interface
done with Field interface
base field implementation
implement part of required methods
final Field implementation class
add getters for static constants
extend erase field and setCellValue methods
implement isDraw()
implement getCellValue
implement getWinner
add haveWinner stub
add win line directions
implement winnercheck
add testing class
init field on instance creation
reinit field on size change
fix ArrayIndexOutOfBoundsException
is not a stub anymore
check for enough turns to win
add test statements