@Override
        public int hashCode() {
            final int PRIME = 59;
            int result = 1;
            result = result * PRIME + (int) (Double.doubleToLongBits(this.amount) >>> 32 ^ Double.doubleToLongBits(this.amount));
            return result;
        }
Represents a fixed amount, calls to {@link #getAmount} will always return
the same fixed value.
helper/src/main/java/me/lucko/helper/random/VariableAmount.java