code: def groupselectmin(table, key, value, presorted=False, buffersize=None,
                     tempdir=None, cache=True):
      
  
      return groupselectfirst(sort(table, value, reverse=False), key,
                              presorted=presorted, buffersize=buffersize,
                              tempdir=tempdir, cache=cache)
docs: Group by the `key` field then return the row with the minimum of the
      `value` field within each group. N.B., will only return one row for each
      group, even if multiple rows have the same (minimum) value.