Constructor for an IncrementalEncoder instance.
All incremental encoders must provide this constructor interface. They are
free to add additional keyword arguments, but only the ones defined
here are used by the Python codec registry.
The IncrementalEncoder may implement different error handling
schemes by providing the errors keyword argument. These
parameters are predefined:
'strict' Raise ValueError (or a subclass);
this is the default.
'ignore' Ignore the character and continue with the next.
'replace' Replace with a suitable replacement character
'xmlcharrefreplace' Replace with the appropriate XML
character reference
'backslashreplace' Replace with backslashed escape sequences.
The errors argument will be assigned to an attribute of the
same name. Assigning to this attribute makes it possible to switch
between different error handling strategies during the lifetime
of the IncrementalEncoder object.
The set of allowed values for the errors argument can
be extended with register_error().