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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 get_kb_mapping(kb_name="", key="", value="", match_type="e", default="", limit=None):
 """Get one unique mapping. If not found, return default. :param kb_name: the name of the kb :param key: include only lines matching this on left side in the results :param value: include only lines matching this on right side in the results :param match_type: s = substring match, e = exact match :param default: default value if no mapping is found :return: a mapping """

    mappings = get_kb_mappings(kb_name, key=key, value=value,
                               match_type=match_type, limit=limit)

    if len(mappings) == 0:
        return default
    else:
        return mappings[0]