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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 merge_configurations(configurations):
 """Merge configurations together and raise error if a conflict is detected :param configurations: configurations to merge together :type configurations: list of :attr:`~pyextdirect.configuration.Base.configuration` dicts :return: merged configurations as a single one :rtype: dict """

    configuration = {}
    for c in configurations:
        for k, v in c.iteritems():
            if k in configuration:
                raise ValueError('%s already in a previous base configuration' % k)
            configuration[k] = v
    return configuration