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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 copy_with_new_str(self, new_str):
 """Copies the current FmtStr's attributes while changing its string."""

        # What to do when there are multiple Chunks with conflicting atts?
        old_atts = dict((att, value) for bfs in self.chunks
                    for (att, value) in bfs.atts.items())
        return FmtStr(Chunk(new_str, old_atts))