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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def insert(self, value):
 """Insert an occurrence of `value` into the btree."""

        i = 0
        n = len(self._tree)
        while i < n:
            cur = self._tree[i]
            self._counts[i] += 1
            if value < cur:
                i = 2 * i + 1
            elif value > cur:
                i = 2 * i + 2
            else:
                return
        raise ValueError("Value %s not contained in tree." "Also, the counts are now messed up." % value)