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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def add(self, crash):
 """ Adds a new crash to the container. If the crash appears to be already known, it's ignored. @see: L{Crash.key} @type crash: L{Crash} @param crash: Crash object to add. """

        if crash not in self:
            key  = crash.key()
            skey = self.marshall_key(key)
            data = self.marshall_value(crash, storeMemoryMap = True)
            self.__db[skey] = data