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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 add_network(self, network, netmask, area=0):
 """Adds a network to be advertised by OSPF Args: network (str):
 The network to be advertised in dotted decimal notation netmask (str):
 The netmask to configure area (str):
 The area the network belongs to. By default this value is 0 Returns: bool: True if the command completes successfully Exception: ValueError: This will get raised if network or netmask are not passed to the method """

        if network == '' or netmask == '':
            raise ValueError('network and mask values '
                             'may not be empty')
        cmd = 'network {}/{} area {}'.format(network, netmask, area)
        return self.configure_ospf(cmd)