def add(self, value):
        """
        Add a value to the buffer.
        """
        ind = int(self._ind % self.shape)
        self._pos = self._ind % self.shape
        self._values[ind] = value
        if self._ind < self.shape:
            self._ind += 1  # fast fill
        else:
            self._ind += self._splitValue
            self._splitPos += self._splitValue
        self._cached = False
Add a value to the buffer.