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RN if node has no children, we claim that the position is either with checkmate or with stalemate. While it's correct generally, it works wrong for the deepest layer (we simply don't generate children for nodes there)

Get this error every time in "5r1k/2R3Rp/8/8/8/8/8/K7 w - - 0 1" position with tree depth 5 after some time of running the program. Not tested on Linux yet

The function Node::updateParentsPositionValue() is currently not used, cause it works wrong in case of zugzwangs.

Example case
Node N has position value X. All children are created, we don't have any better value (in terms of MiniMax), so N still has value X. But after creating all possible grandchildren it's obvious, that position has zugzwang, and any move makes position value worse. But Node::updateParentsPositionValue() can't update N's value, because it's smaller than all children have. Is it actually possible to update position value without checking all the children?

If the black (and only black) king is located on h8 field, and white take any piece with check, it becomes white for some reason