<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def read_associations(assoc_fn, anno_type='id2gos', **kws):
 """Return associatinos in id2gos format"""

    # kws get_objanno: taxids hdr_only prt allow_missing_symbol
    obj = get_objanno(assoc_fn, anno_type, **kws)
    # kws get_id2gos: ev_include ev_exclude keep_ND keep_NOT b_geneid2gos go2geneids
    return obj.get_id2gos(**kws)