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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 ClearCallHistory(self, Username='ALL', Type=chsAllCalls):
 """Clears the call history. :Parameters: Username : str Skypename of the user. A special value of 'ALL' means that entries of all users should be removed. Type : `enums`.clt* Call type. """

        cmd = 'CLEAR CALLHISTORY %s %s' % (str(Type), Username)
        self._DoCommand(cmd, cmd)