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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 goto_definitions(self):
 """ Return the definition of a the symbol under the cursor via exact match. Goes to that definition with a buffer. """

        element = self._evaluator.get_definition()
        if element is not None:
            return BaseDefinition(self._user_context, element)
        else:
            return None