You can do the same thing for the Contract class, as shown in Listing 3.
您可以为contract类做相同的事情，如清单3所示。
Your contract interface can also inherit this class.
您的合约介面也可以继承这个类别。
Obtain structure of national bldg. company to decorate adornment project major to contract 2 class aptitude.
获国家建筑业企业建筑装修装饰工程专业承包二级资质。
Obtain structure of national bldg. company to decorate adornment project major to contract 2 class aptitude.
获国家建筑业企业建筑装修装饰工程专业承包二级资质。
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