def _fill(inst_class, frequencies):
 ctype_info = inst_class.get_flat_type_info(inst_class)
 cfreq_key = (inst_class, 0)
 for (k, v) in ctype_info.items():
  if (v.Attributes.min_occurs > 0):
   frequencies[cfreq_key][k] = 0

def _fill ( inst_class , frequencies ) : ctype_info = inst_class . get_flat_type_info ( inst_class ) cfreq_key = ( inst_class , 0 ) for ( k , v ) in ctype_info . items ( ) : if ( v . Attributes . min_occurs > 0 ) : frequencies [ cfreq_key ] [ k ] = 0
this function initializes the frequencies dict with null values .