def __init__(self, source_ref, target_ref):
if source_ref is None or not isinstance(source_ref, str):<EOL><INDENT>raise TypeError("<STR_LIT>")<EOL><DEDENT>if target_ref is None or not isinstance(source_ref, str):<EOL><INDENT>raise TypeError("<STR_LIT>")<EOL><DEDENT>super(SequenceFlow, self).__init__()<EOL>self.__source_ref = source_ref<EOL>self.__target_ref = target_ref<EOL>self.__condition_expression = None<EOL>self.__is_immediate = None<EOL>
Default constructor, initializes object fields with new instances.