int function ( ) { return pref_group_len ; }
get the preferred group length . concode_field_sep int MIN_ALLOWED concode_elem_sep int MAX_ALLOWED concode_elem_sep int min_group_len concode_elem_sep int max_group_len concode_elem_sep int pref_group_len concode_field_sep int getMax_group_len concode_elem_sep int getMin_group_len