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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_all_database_accessions(chebi_ids):
    '''Returns all database accessions'''
    all_database_accessions = [get_database_accessions(chebi_id)
                               for chebi_id in chebi_ids]
    return [x for sublist in all_database_accessions for x in sublist]