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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 define(self, value, lineno, namespace=None):
 """ Defines label value. It can be anything. Even an AST """

        if self.defined:
            error(lineno, "label '%s' already defined at line %i" % (self.name, self.lineno))

        self.value = value
        self.lineno = lineno
        self.namespace = NAMESPACE if namespace is None else namespace