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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 active_qubits(linear, quadratic):
 """Calculate a set of all active qubits. Qubit is "active" if it has bias or coupling attached. Args: linear (dict[variable, bias]/list[variable, bias]):
 Linear terms of the model. quadratic (dict[(variable, variable), bias]):
 Quadratic terms of the model. Returns: set: Active qubits' indices. """


    active = {idx for idx,bias in uniform_iterator(linear)}
    for edge, _ in six.iteritems(quadratic):
        active.update(edge)
    return active