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class ChainableReverseAbstractInterpreter {
      public JSType caseFunctionType(FunctionType type) {
        return type;
      }
}

class ChainableReverseAbstractInterpreter {
      public JSType caseFunctionType(FunctionType type) {
        return type;
      }
}

class ChainableReverseAbstractInterpreter.RestrictByTrueTypeOfResultVisitor {
    public JSType caseFunctionType(FunctionType type) {
      return null;
    }
}

class ChainableReverseAbstractInterpreter.RestrictByFalseTypeOfResultVisitor {
    public JSType caseFunctionType(FunctionType type) {
      return type;
    }
}

class ChainableReverseAbstractInterpreter.RestrictByOneTypeOfResultVisitor {
    public JSType caseFunctionType(FunctionType type) {
      return matchesExpectation("function") ? type : null;
    }

}