def set_process_ref(self, value):
if not isinstance(value, str):<EOL><INDENT>raise TypeError("<STR_LIT>")<EOL><DEDENT>self.__process_ref = value<EOL>
Setter for 'process_ref' field.
:param value - a new value of 'process_ref' field. Must be either None (process_ref is optional according to
BPMN 2.0 XML Schema) or String.