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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 setCustomCompletions(self, wordSet):
 """Add a set of custom completions to the editors completions. This set is managed independently of the set of keywords and words from the current document, and can thus be changed at any time. """

        if not isinstance(wordSet, set):
            raise TypeError('"wordSet" is not a set: %s' % type(wordSet))
        self._completer.setCustomCompletions(wordSet)