Returns a new instance with each amount _in this period negated.
!(p)
This returns a period with each of the years, months and days units
individually negated.
For example, a period of "2 years, -3 months and 4 days" will be
negated to "-2 years, 3 months and -4 days".
No normalization is performed.
@return a {@code Period} based on this period with the amounts negated, not null
@throws ArithmeticException if numeric overflow occurs, which only happens if
one of the units has the value {@code Long.MIN_VALUE}
Returns a new instance with each amount _in this period negated. !(p) This returns a period with each of the years, months and days units individually negated. For example, a period of "2 years, -3 months and 4 days" will be negated to "-2 years, 3 months and -4 days". No normalization is performed.
@return a {@code Period} based on this period with the amounts negated, not null @throws ArithmeticException if numeric overflow occurs, which only happens if one of the units has the value {@code Long.MIN_VALUE}