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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 fork(self, strictindex, new_value):
 """ Return a chunk referring to the same location in a duplicated document. Used when modifying a YAML chunk so that the modification can be validated before changing it. """

        forked_chunk = YAMLChunk(
            deepcopy(self._ruamelparsed),
            pointer=self.pointer,
            label=self.label,
            key_association=copy(self._key_association),
        )
        forked_chunk.contents[self.ruamelindex(strictindex)] = new_value.as_marked_up()
        forked_chunk.strictparsed()[strictindex] = deepcopy(new_value.as_marked_up())
        return forked_chunk