old_contents: """Extensions of standard exceptions for PyWXSB events.
  
  Yeah, I'd love this module to be named exceptions.py, but it can't
  because the standard library has one of those, and we need to
  reference it below.
  """
  
  import exceptions
  
  class PyWXSBException (exceptions.Exception):
      """Base class for exceptions that indicate a problem that the user should fix."""
      pass
  
  class SchemaValidationError (PyWXSBException):
      """Raised when the XML hierarchy does not appear to be valid for an XML schema."""
      pass
  
  class BadTypeValueError (PyWXSBException):
      """Raised when a value in an XML attribute does not conform to the simple type."""
      pass
  
  class NotInNamespaceError (PyWXSBException):
      '''Raised when a name is referenced that is not defined in the appropriate namespace.'''
      __namespace = None
      __ncName = None
  
  class BadPropertyError (PyWXSBException):
      """Raised when a schema component property is accessed on a component instance that does not define that property."""
      pass
  
  class BadDocumentError (PyWXSBException):
      """Raised when processing document content and an error is encountered."""
      pass
  
  class StructuralBadDocumentError (BadDocumentError):
      """Raised when processing document and the content model is not satisfied."""
  
  class UnrecognizedContentError (StructuralBadDocumentError):
      """Raised when processing document and an element does not match the content model."""
  
  class UnrecognizedElementError (UnrecognizedContentError):
      """Raised when creating an instance from a document with an unrecognized root element."""
  
  class ExtraContentError (StructuralBadDocumentError):
      """Raised when processing document and there is more material in an element content than expected."""
  
  class MissingContentError (StructuralBadDocumentError):
      """Raised when processing document and expected content is not present.  See also UnrecognizedContentError."""
  
  class NotAnElementError (UnrecognizedElementError):
      """Raised when processing document and a tag that is a type but not an element is encountered."""
  
  class UnrecognizedAttributeError (BadDocumentError):
      """Raised when an attribute is found that is not sanctioned by the content model."""
  
  class ProhibitedAttributeError (BadDocumentError):
      """Raised when an attribute that is prohibited is provided in an element."""
  
  class MissingAttributeError (BadDocumentError):
      """Raised when an attribute that is required is missing in an element."""
  
  class AttributeChangeError (BadDocumentError):
      """Raised when an attribute with a fixed value constraint is set to a different value."""
  
  class DOMGenerationError (PyWXSBException):
      """Raised when converting binding to DOM and something goes wrong."""
      pass
  
  class PyWXSBError (exceptions.Exception):
      """Base class for exceptions that indicate a problem that the user probably can't fix."""
      pass
      
  class LogicError (PyWXSBError):
      """Raised when the code detects an implementation problem."""
  
  class IncompleteImplementationError (LogicError):
      """Raised when a code branch is taken that has not yet been implemented."""
  
new_contents: """Extensions of standard exceptions for PyWXSB events.
  
  Yeah, I'd love this module to be named exceptions.py, but it can't
  because the standard library has one of those, and we need to
  reference it below.
  """
  
  import exceptions
  
  class PyWXSBException (exceptions.Exception):
      """Base class for exceptions that indicate a problem that the user should fix."""
      pass
  
  class SchemaValidationError (PyWXSBException):
      """Raised when the XML hierarchy does not appear to be valid for an XML schema."""
      pass
  
  class NamespaceUniquenessError (PyWXSBException):
      """Raised when an attempt is made to record multiple objects of the same name in the same namespace category."""
      pass
  
  class BadTypeValueError (PyWXSBException):
      """Raised when a value in an XML attribute does not conform to the simple type."""
      pass
  
  class NotInNamespaceError (PyWXSBException):
      '''Raised when a name is referenced that is not defined in the appropriate namespace.'''
      __namespace = None
      __ncName = None
  
  class BadPropertyError (PyWXSBException):
      """Raised when a schema component property is accessed on a component instance that does not define that property."""
      pass
  
  class BadDocumentError (PyWXSBException):
      """Raised when processing document content and an error is encountered."""
      pass
  
  class StructuralBadDocumentError (BadDocumentError):
      """Raised when processing document and the content model is not satisfied."""
  
  class UnrecognizedContentError (StructuralBadDocumentError):
      """Raised when processing document and an element does not match the content model."""
  
  class UnrecognizedElementError (UnrecognizedContentError):
      """Raised when creating an instance from a document with an unrecognized root element."""
  
  class ExtraContentError (StructuralBadDocumentError):
      """Raised when processing document and there is more material in an element content than expected."""
  
  class MissingContentError (StructuralBadDocumentError):
      """Raised when processing document and expected content is not present.  See also UnrecognizedContentError."""
  
  class NotAnElementError (UnrecognizedElementError):
      """Raised when processing document and a tag that is a type but not an element is encountered."""
  
  class UnrecognizedAttributeError (BadDocumentError):
      """Raised when an attribute is found that is not sanctioned by the content model."""
  
  class ProhibitedAttributeError (BadDocumentError):
      """Raised when an attribute that is prohibited is provided in an element."""
  
  class MissingAttributeError (BadDocumentError):
      """Raised when an attribute that is required is missing in an element."""
  
  class AttributeChangeError (BadDocumentError):
      """Raised when an attribute with a fixed value constraint is set to a different value."""
  
  class DOMGenerationError (PyWXSBException):
      """Raised when converting binding to DOM and something goes wrong."""
      pass
  
  class PyWXSBError (exceptions.Exception):
      """Base class for exceptions that indicate a problem that the user probably can't fix."""
      pass
      
  class LogicError (PyWXSBError):
      """Raised when the code detects an implementation problem."""
  
  class IncompleteImplementationError (LogicError):
      """Raised when a code branch is taken that has not yet been implemented."""
  
subject: Add a distinct exception for namespace collisions