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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 camel_case(snake_str):
 """ Returns a camel-cased version of a string. :param a_string: any :class:`str` object. Usage: "fooBar" """


    components = snake_str.split('_')
    # We capitalize the first letter of each component except the first one
    # with the 'title' method and join them together.
    return components[0] + "".join(x.title() for x in components[1:])