when did patient 95057 get the anion gap lab test for the last time during their current hospital encounter?
select labevents.charttime from labevents where labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'anion gap' ) and labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 95057 and admissions.dischtime is null ) order by labevents.charttime desc limit 1