obtains the names of the registered schemes . concode_field_sep ConcurrentHashMap<String,Scheme> registeredSchemes concode_field_sep Scheme getScheme concode_elem_sep Scheme getScheme concode_elem_sep Scheme get concode_elem_sep void setItems concode_elem_sep Scheme unregister concode_elem_sep Scheme register
List < String > function ( ) { return new ArrayList < String > ( registeredSchemes . keySet ( ) ) ; }