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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 from_json(buffer, auto_flatten=True, raise_for_index=True):
 """Parses a JSON string into either a view or an index. If auto flatten is enabled a sourcemap index that does not contain external references is automatically flattened into a view. By default if an index would be returned an `IndexedSourceMap` error is raised instead which holds the index. """

    buffer = to_bytes(buffer)

    view_out = _ffi.new('lsm_view_t **')
    index_out = _ffi.new('lsm_index_t **')

    buffer = to_bytes(buffer)
    rv = rustcall(
        _lib.lsm_view_or_index_from_json,
        buffer, len(buffer), view_out, index_out)
    if rv == 1:
        return View._from_ptr(view_out[0])
    elif rv == 2:
        index = Index._from_ptr(index_out[0])
        if auto_flatten and index.can_flatten:
            return index.into_view()
        if raise_for_index:
            raise IndexedSourceMap('Unexpected source map index',
                                   index=index)
        return index
    else:
        raise AssertionError('Unknown response from C ABI (%r)' % rv)