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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 add_grouping(state_collection, grouping_name, loaded_processes, overriding_parameters=None):
 """ Adds a grouping to a state collection by using the process selected by the grouping name Does not override existing groupings """

    if (
        grouping_name not in state_collection.groupings and
        loaded_processes != None and
        loaded_processes["grouping_selector"].get(grouping_name) != None
    ):
        state_collection = loaded_processes["grouping_selector"][grouping_name].process_function(state_collection,overriding_parameters)
    return state_collection