Exact mass and natural abundance is not preserved on reading/writing CML. As these attributes are boxed primitives they can be null and throw an exception when unboxed by 'assertEquals'. Before checking the values the attributes are not checked for nullity.

Change-Id: If6b52cf6f22d23405b8f15045d8ca1dccf0bcd74
Signed-off-by: Egon Willighagen <egonw@users.sourceforge.net>