question: public static StringBuffer appendNumber ( StringBuffer result , int n , int radix , int minDigits ) throws IllegalArgumentException { if ( radix < 2 || radix > 36 ) { throw new IllegalArgumentException ( "Illegal radix " + radix ) ; } int abs = n ; if ( n < 0 ) { abs = - n ; result . append ( "-" ) ; } recursiveAppendNumber ( result , abs , radix , minDigits ) ; return result ; }
target:  Append a number to the given StringBuffer in the given radix. Standard digits '0'-'9' are used and letters 'A'-'Z' for radices 11 through 36.