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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 func(data_row, wait):
    ''' A sample function
    It takes 'wait' seconds to calculate the sum of each row
    '''
    time.sleep(wait)
    data_row['sum'] = data_row['col_1'] + data_row['col_2']
    return data_row