text: class Key:
      def __init__ (self, data):
          self.data = data
  
      def __str__ (self):
          return str (self.data)
  
  SHP = Key ('SHP')
  POSTGRES = Key ('POSTGRES')
  GEOSERVER = Key ('GEOSERVER')
  
  POLYGON = Key ('POLYGON')
  POINT = Key ('POINT')
  
  ONE_TO_ONE = Key ('ONE_TO_ONE')
  MANY_TO_ONE = Key ('MANY_TO_ONE')
  