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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 _parse_param(key, val):
 """ Parse the query param looking for sparse fields params Ensure the `val` or what will become the sparse fields is always an array. If the query param is not a sparse fields query param then return None. :param key: the query parameter key in the request (left of =) :param val: the query parameter val in the request (right of =) :return: tuple of resource type to implement the sparse fields on & a array of the fields. """


    regex = re.compile(r'fields\[([A-Za-z]+)\]')
    match = regex.match(key)

    if match:
        if not isinstance(val, list):
            val = val.split(',')

        fields = [field.lower() for field in val]
        rtype = match.groups()[0].lower()

        return rtype, fields