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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 resource_md5(self, resource):
 """Return the stored MD5 sum for a particular named resource."""

        if not(resource in self.contents['md5']):
            raise ValueError("No such resource %r in refpkg" % (resource,))
        return self.contents['md5'][resource]