def combine(self) -> bool:
        """Turn this Block into a leaf based on the majority colour of its
        children.

        The majority colour is the colour with the most child blocks of that
        colour. A tie does not constitute a majority (e.g., if there are two red
        children and two blue children, then there is no majority colour).

        If there is no majority colour, do nothing. If this block is not at a
        level of max_depth - 1, or this block has no children, do nothing.

        Return True iff this Block was turned into a leaf node.
        """
        # TODO: Implement me
        if self.level != self.max_depth - 1 or len(self.children) == 0:
            return False
        else:
            d = {}

            for c in self.children:
                if c.colour not in d:
                    d[c.colour] = 1
                else:
                    d[c.colour] += 1

            m = 0
            clr = None
            for i in d:
                if d[i] > m:
                    m = d[i]
                    clr = i

            # checking for duplicates
            for i in d:
                if d[i] == m and clr != i:
                    return False
            return True

    def create_copy(self) -> Block:
        """Return a new Block that is a deep copy of this Block.

        Remember that a deep copy has new blocks (not aliases) at every level.
        """
        # TODO: Implement me
        copy = Block(self.position, self.size, self.colour, self.level,
                     self.max_depth)

        for child in self.children:
            copy.children.append(child.create_copy())

        return copy