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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 from_untrusted(cls, value, lineno=None, environment=None):
 """Return a const object if the value is representable as constant value in the generated code, otherwise it will raise an `Impossible` exception. """

        from .compiler import has_safe_repr
        if not has_safe_repr(value):
            raise Impossible()
        return cls(value, lineno=lineno, environment=environment)