private boolean isKeyRangeAntiValue(final Buffer buffer1, final int foundAt1, final Buffer buffer2,
            final int foundAt2) {
        if (buffer1.getKeyBlockEnd() != (foundAt1 & P_MASK) + KEYBLOCK_LENGTH) {
            return false;
        }
        if (buffer2.getKeyBlockStart() != (foundAt2 & P_MASK) - KEYBLOCK_LENGTH) {
            return false;
        }
        if (buffer1.getRightSibling() != buffer2.getPageAddress()) {
            return false;
        }
        return buffer2.isPrimordialAntiValue(Buffer.KEY_BLOCK_START);
    }