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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 unique(self, e, **kwargs):
 """ Returns True if the expression `e` has only one solution by querying the constraint solver. It does also add that unique solution to the solver's constraints. """

        if not isinstance(e, claripy.ast.Base):
            return True

        # if we don't want to do symbolic checks, assume symbolic variables are multivalued
        if o.SYMBOLIC not in self.state.options and self.symbolic(e):
            return False

        r = self.eval_upto(e, 2, **kwargs)
        if len(r) == 1:
            self.add(e == r[0])
            return True
        elif len(r) == 0:
            raise SimValueError("unsatness during uniqueness check(ness)")
        else:
            return False