a method to list elastic ip addresses associated with account on AWS
            
        :param tag_values: [optional] list of tag values
        :return: list of strings with ip addresses

def list_addresses(self, tag_values=None):
        
        '''
            a method to list elastic ip addresses associated with account on AWS
            
        :param tag_values: [optional] list of tag values
        :return: list of strings with ip addresses
        '''
        
        title = '%s.list_addresses' % self.__class__.__name__

    # validate inputs
        input_fields = {
            'tag_values': tag_values
        }
        for key, value in input_fields.items():
            if value:
                object_title = '%s(%s=%s)' % (title, key, str(value))
                self.fields.validate(value, '.%s' % key, object_title)
            
    # add tags to method arguments
        kw_args = {}
        tag_text = ''
        if tag_values:
            kw_args = {
                'Filters': [ { 'Name': 'tag-value', 'Values': tag_values } ]
            }
            from labpack.parsing.grammar import join_words
            plural_value = ''
            if len(tag_values) > 1:
                plural_value = 's'
            tag_text = ' with tag value%s %s' % (plural_value, join_words(tag_values))
    
    # report query
        self.iam.printer('Querying AWS region %s for elastic ip addresses%s.' % (self.iam.region_name, tag_text))
        address_list = []
        
    # discover details associated with instance id
        try:
            response = self.connection.describe_addresses(**kw_args)
        except:
            raise AWSConnectionError(title)

    # populate address list with response
        response_list = response['Addresses']
        for address in response_list:
            address_list.append(address['PublicIp'])

        return address_list