old_contents: from katagawa.orm.schema import table_base, Column
  from katagawa.orm.schema.types import BigInt, Integer, String, Text, ColumnType
  
  
  class Boolean(ColumnType):
      true = ('TRUE', 't', 'true', 'y', 'yes', 'on', '1')
      false = ('FALSE', 'f', 'false', 'n', 'no', 'off', '0')
  
      @staticmethod
      def sql():
          return 'BOOLEAN'
  
      @staticmethod
      def cast(value):
          if value:
              return 'TRUE'
          else:
              return 'FALSE'
  
      @classmethod
      def reverse_cast(cls, sql):
          if sql in cls.true:
              return True
          elif sql in cls.false:
              return False
          else:
              raise ValueError
  
  
  Table = table_base()
  
  
  class Commodity(Table):
      id = Column(Integer, primary_key=True)
      name = Column(Text)
      average_price = Column(Integer)
      is_rare = Column(Boolean)
      category = Column(Text)
  
  
  class System(Table):
      id = Column(Integer, primary_key=True)
      name = Column(Text)
      population = Column(BigInt)
      primary_economy = Column(Text)
      government = Column(Text)
      allegiance = Column(Text)
      state = Column(Text)
      security = Column(Text)
      power = Column(Text)
  
  
  class Station(Table):
      id = Column(Integer, primary_key=True)
      system_id = Column(Integer)
      name = Column(Text)
      max_landing_pad_size = Column(Text)
      distance_to_star = Column(Integer)
      government = Column(Text)
      allegiance = Column(Text)
      state = Column(Text)
      type = Column(Text)
      has_blackmarket = Column(Boolean)
      has_commodities = Column(Boolean)
      import_commodities = Column(Text)
      export_commodities = Column(Text)
      prohibited_commodities = Column(Text)
      economies = Column(Text)
      is_planetary = Column(Boolean)
      selling_ships = Column(Text)
  
  
  class Listing(Table):
      id = Column(Integer, primary_key=True)
      station_id = Column(Integer)
      commodity_id = Column(Integer)
      supply = Column(Integer)
      buy_price = Column(Integer)
      sell_price = Column(Integer)
      demand = Column(Integer)
      collected_at = Column(Text)
  
new_contents: from katagawa.orm.schema import table_base, Column
  from katagawa.orm.schema.types import BigInt, Integer, String, Text, ColumnType
  
  
  class Boolean(ColumnType):
      @staticmethod
      def sql():
          return 'BOOLEAN'
  
  
  Table = table_base()
  
  
  class Commodity(Table):
      id = Column(Integer, primary_key=True)
      name = Column(Text)
      average_price = Column(Integer)
      is_rare = Column(Boolean)
      category = Column(Text)
  
  
  class System(Table):
      id = Column(Integer, primary_key=True)
      name = Column(Text)
      population = Column(BigInt)
      primary_economy = Column(Text)
      government = Column(Text)
      allegiance = Column(Text)
      state = Column(Text)
      security = Column(Text)
      power = Column(Text)
  
  
  class Station(Table):
      id = Column(Integer, primary_key=True)
      system_id = Column(Integer)
      name = Column(Text)
      max_landing_pad_size = Column(Text)
      distance_to_star = Column(Integer)
      government = Column(Text)
      allegiance = Column(Text)
      state = Column(Text)
      type = Column(Text)
      has_blackmarket = Column(Boolean)
      has_commodities = Column(Boolean)
      import_commodities = Column(Text)
      export_commodities = Column(Text)
      prohibited_commodities = Column(Text)
      economies = Column(Text)
      is_planetary = Column(Boolean)
      selling_ships = Column(Text)
  
  
  class Listing(Table):
      id = Column(Integer, primary_key=True)
      station_id = Column(Integer)
      commodity_id = Column(Integer)
      supply = Column(Integer)
      buy_price = Column(Integer)
      sell_price = Column(Integer)
      demand = Column(Integer)
      collected_at = Column(Text)
  
subject: Remove unused functions from Boolean