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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 normalizeBPointType(value):
 """ Normalizes bPoint type. * **value** must be an string. * **value** must be one of the following: +--------+ | corner | +--------+ | curve | +--------+ * Returned value will be an unencoded ``unicode`` string. """

    allowedTypes = ['corner', 'curve']
    if not isinstance(value, basestring):
        raise TypeError("bPoint type must be a string, not %s."
                        % type(value).__name__)
    if value not in allowedTypes:
        raise ValueError("bPoint type must be 'corner' or 'curve', not %r."
                         % value)
    return unicode(value)