question: @ NotNull default B append ( double d , int decimalPlaces ) throws BufferOverflowException { if ( decimalPlaces < 20 ) { double d2 = d * Maths . tens ( decimalPlaces ) ; if ( d2 <= Long . MAX_VALUE && d2 >= Long . MIN_VALUE ) { return appendDecimal ( Math . round ( d2 ) , decimalPlaces ) ; } } return append ( d ) ; }
target:  Append a double in decimal notation to a specific number of decimal places. Trailing zeros are not truncated. <p> If the number would normally be printed with more decimal places, the number is rounded.