question: @ Override public String toString ( ) { StringBuffer sb = new StringBuffer ( bits . length / 2 ) ; int bitCount = 0 ; sb . append ( '{' ) ; boolean comma = false ; for ( int i = 0 ; i < bits . length ; i ++ ) { if ( bits [ i ] == 0 ) { bitCount += ELM_SIZE ; continue ; } for ( int j = 0 ; j < ELM_SIZE ; j ++ ) { if ( ( ( bits [ i ] & ( TWO_N_ARRAY [ j ] ) ) != 0 ) ) { if ( comma ) { sb . append ( ", " ) ; } sb . append ( bitCount ) ; comma = true ; } bitCount ++ ; } } sb . append ( '}' ) ; return sb . toString ( ) ; }
target:  Returns a string containing a concise, human-readable description of the receiver.