@classmethod
def from_json(cls, json_obj):
    """
        Constructs a Variable from the provided json-object.

        Example
        --------
        >>> import json
        >>> with open("path_to_file.json") as infile:
        >>>     var = Variable.from_json(json.load(infile))
        """
    return cls(json_obj['name'], lb=json_obj['lb'], ub=json_obj['ub'], type
        =json_obj['type'])
