a method to retrieve all the locations tracked by the model
            
        :return: dictionary with location id keys
        
        NOTE:   results are added to self.locations property
        
        {
            'location.id': {
                '
            }
        }

def get_locations(self):

        '''
            a method to retrieve all the locations tracked by the model
            
        :return: dictionary with location id keys
        
        NOTE:   results are added to self.locations property
        
        {
            'location.id': {
                '
            }
        }
        '''
        
        import requests
        url = self.endpoint + '/locations'
        params = {
            'group': self.group_name
        }
        response = requests.get(url, params=params)
        response_details = response.json()
        if 'locations' in response_details.keys():
            self.locations = response_details['locations']
            
        return self.locations