<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def getWSDL(self):
 """Return the WSDL object that contains this information item."""

        parent = self
        while 1:
            # skip any collections
            if isinstance(parent, WSDL):
                return parent
            try: parent = parent.parent()
            except: break
            
        return None