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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 id(self):
 """id property based on server_and_prefix and identifier."""

        id = ''
        if (self.server_and_prefix is not None and
                self.server_and_prefix != ''):
            id += self.server_and_prefix + '/'
        if (self.identifier is not None):
            id += self.identifier
        return id