Lookup the variables in the provided dictionary, resolve with entries
        in the context

def context_lookup(self, vars):
        """
        Lookup the variables in the provided dictionary, resolve with entries
        in the context
        """
        while isinstance(vars, IscmExpr):
            vars = vars.resolve(self.context)
        #
        for (k,v) in vars.items():
            if isinstance(v, IscmExpr):
                vars[k] = v.resolve(self.context)
        return vars