code: def trigger_installed(connection: connection, table: str, schema: str='public'):
      
      installed = False
  
      log('Checking if {}.{} trigger installed...'.format(schema, table), logger_name=_LOGGER_NAME)
  
      statement = SELECT_TRIGGER_STATEMENT.format(
          table=table,
          schema=schema
      )
  
      result = execute(connection, statement)
      if result:
          installed = True
  
      log('...{}installed'.format('' if installed else 'NOT '), logger_name=_LOGGER_NAME)
  
      return installed
docs: Test whether or not a psycopg2-pgevents trigger is installed for a table.
  
      Parameters
      ----------
      connection: psycopg2.extensions.connection
          Active connection to a PostGreSQL database.
      table: str
          Table whose trigger-existence will be checked.
      schema: str
          Schema to which the table belongs.
  
      Returns
      -------
      bool
          True if the trigger is installed, otherwise False.