question: private static void format ( StringBuffer target , int scale , long intP , long decP ) { if ( decP != 0L ) { decP += 5L ; decP /= 10L ; if ( decP >= tenPowDouble ( scale ) ) { intP ++ ; decP -= tenPow ( scale ) ; } if ( decP != 0L ) { while ( decP % 10L == 0L ) { decP = decP / 10L ; scale -- ; } } } target . append ( intP ) ; if ( decP != 0L ) { target . append ( '.' ) ; while ( scale > 0 && ( scale > 18 ? decP < tenPowDouble ( -- scale ) : decP < tenPow ( -- scale ) ) ) { target . append ( '0' ) ; } target . append ( decP ) ; } }
target:  Helper method to do the custom rounding used within formatDoublePrecise