Multiply this instance with a number representing millis and return a new Duration. If the called Duration instance is INDEFINITE, return INDEFINITE. If the called Duration instance is UNKNOWN, return UNKNOWN. This method does not change the value of the called Duration instance.

Parameters:

n

the amount to multiply by in fractional milliseconds

Returns:  the result of multiplying this duration with n. This is the same as millis * n using double arithmetic