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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 _expand_tasks(self, scopes):
 """Add all tasks in any requested goals. Returns the requested scopes, plus the added tasks, sorted by scope name. """

    expanded_scopes = set(scopes)
    for scope, info in self._scope_to_info.items():
      if info.category == ScopeInfo.TASK:
        outer = enclosing_scope(scope)
        while outer != GLOBAL_SCOPE:
          if outer in expanded_scopes:
            expanded_scopes.add(scope)
            break
          outer = enclosing_scope(outer)
    return sorted(expanded_scopes)