def AddConstant(self, other):
pmf = Pmf()<EOL>for v1, p1 in self.Items():<EOL><INDENT>pmf.Set(v1 + other, p1)<EOL><DEDENT>return pmf<EOL>
Computes the Pmf of the sum a constant and  values from self.

        other: a number

        returns: new Pmf