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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 setDefaults(configObj={}):
 """ Return a dictionary of the default parameters which also been updated with the user overrides. """

    paramDict = {
        'gain': 7,           # Detector gain, e-/ADU
        'grow': 1,           # Radius around CR pixel to mask [default=1 for
                             #     3x3 for non-NICMOS]
        'ctegrow': 0,        # Length of CTE correction to be applied
        'rn': 5,             # Read noise in electrons
        'snr': '4.0 3.0',    # Signal-to-noise ratio
        'scale': '0.5 0.4',  # scaling factor applied to the derivative
        'backg': 0,          # Background value
        'expkey': 'exptime'  # exposure time keyword
    }

    if len(configObj) > 0:
        for key in configObj:
            paramDict[key] = configObj[key]

    return paramDict