text: # Imports
  
  # noinspection PyUnresolvedReferences
  from sqlalchemy.exc import OperationalError, ProgrammingError, ResourceClosedError
  
  # Classes
  
  
  class ImproperlyConfigured(Exception):
      """Indicates a problem with settings."""
      pass
  
  
  class MultipleObjectsReturned(Exception):
      """Indicates a query for a specific record has instead identified multiple records."""
      pass
  
  
  class ObjectDoesNotExist(Exception):
      """Indicates a query for a specific record has no match."""
      pass
  
  
  class UnknownDatabaseBackend(Exception):
      """Indicates the given backend is unknown or unsupported."""
      pass
  