question: public static String toString ( int optionNumber ) { switch ( optionNumber ) { case RESERVED_0 : case RESERVED_1 : case RESERVED_2 : case RESERVED_3 : case RESERVED_4 : return Names . Reserved ; case IF_MATCH : return Names . If_Match ; case URI_HOST : return Names . Uri_Host ; case ETAG : return Names . ETag ; case IF_NONE_MATCH : return Names . If_None_Match ; case URI_PORT : return Names . Uri_Port ; case LOCATION_PATH : return Names . Location_Path ; case URI_PATH : return Names . Uri_Path ; case CONTENT_FORMAT : return Names . Content_Format ; case MAX_AGE : return Names . Max_Age ; case URI_QUERY : return Names . Uri_Query ; case ACCEPT : return Names . Accept ; case LOCATION_QUERY : return Names . Location_Query ; case PROXY_URI : return Names . Proxy_Uri ; case PROXY_SCHEME : return Names . Proxy_Scheme ; case OBSERVE : return Names . Observe ; case BLOCK2 : return Names . Block2 ; case BLOCK1 : return Names . Block1 ; case SIZE2 : return Names . Size2 ; case SIZE1 : return Names . Size1 ; default : return String . format ( "Unknown (%d)" , optionNumber ) ; } }
target:  Returns a string representation of the option number.