old_contents: from sqlalchemy import ForeignKey, Column, String, desc
  from .models import Node, Info
  from information import State
  
  
  class Environment(Node):
  
      """Defines an environment node.
  
      Environments are nodes that have a state and that receive a transmission
      from anyone that observes them.
      """
  
      __tablename__ = "environment"
      __mapper_args__ = {"polymorphic_identity": "environment"}
  
      # the unique environment id
      uuid = Column(String(32), ForeignKey("node.uuid"), primary_key=True)
  
      @property
      def state(self):
          """The state is the most recently created info of type State."""
          return State\
              .query\
              .filter_by(origin_uuid=self.uuid)\
              .order_by(desc(Info.creation_time))\
              .first()
  
      def get_observed(self, by_whom=None):
          """When observed, transmit the state."""
          if not self.has_connection_to(by_whom):
              self.connect_to(by_whom)
          self.transmit(what=self.state, to_whom=by_whom)
  
      def __repr__(self):
          """Print the environment in a nice format."""
          return "Environment-{}-{}".format(self.uuid[:6], self.type)
  
new_contents: from sqlalchemy import ForeignKey, Column, String, desc
  from .models import Node, Info
  from information import State
  
  
  class Environment(Node):
  
      """Defines an environment node.
  
      Environments are nodes that have a state and that receive a transmission
      from anyone that observes them.
      """
  
      __tablename__ = "environment"
      __mapper_args__ = {"polymorphic_identity": "environment"}
  
      # the unique environment id
      uuid = Column(String(32), ForeignKey("node.uuid"), primary_key=True)
  
      @property
      def state(self):
          """The state is the most recently created info of type State."""
          return State\
              .query\
              .filter_by(origin_uuid=self.uuid)\
              .order_by(desc(Info.creation_time))\
              .first()
  
      def get_observed(self, by_whom=None):
          """When observed, transmit the state."""
          self.transmit(what=self.state, to_whom=by_whom)
  
      def __repr__(self):
          """Print the environment in a nice format."""
          return "Environment-{}-{}".format(self.uuid[:6], self.type)
  
subject: Remove side effect where observing connects