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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 map_val(dest, src, key, default=None, src_key=None):
 """Will ensure a dict has values sourced from either another dict or based on the provided default"""

    if not src_key:
        src_key = key

    if src_key in src:
        dest[key] = src[src_key]
    else:
        if default is not None:
            dest[key] = default