def supports_time_types_for_conversion(self, source_time_type=None, target_time_type=None):
Tests if a given time conversion is supported.

        arg:    source_time_type (osid.type.Type): the type of the
                source time
        arg:    target_time_type (osid.type.Type): the type of the
                target time
        return: (boolean) - ``true`` if the given source and target
                conversion is supported, ``false`` otherwise
        raise:  NullArgument - ``source_time_type`` or
                ``target_time_type`` is ``null``
        *compliance: mandatory -- This method must be implemented.*