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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 create_grid_mapping(area):
 """Create the grid mapping instance for `area`."""

    try:
        grid_mapping = mappings[area.proj_dict['proj']](area)
        grid_mapping['name'] = area.proj_dict['proj']
    except KeyError:
        raise NotImplementedError

    return grid_mapping