Error when setting a raw-wrapped value

[HansBug]

>>> from treevalue import FastTreeValue, raw
>>> f['a'] =  raw({'a': 1})
>>> f
<FastTreeValue 0x7f17e8153080>
└── 'a' --> <treevalue.tree.common.base.RawWrapper object at 0x7f17e8146fd0>

This is wrong, the correct one should be

>>> from treevalue import FastTreeValue, raw
>>> f['a'] =  raw({'a': 1})
>>> f
<FastTreeValue 0x7f17e8153080>
└── 'a' --> {'a': 1}