I don't see static initializer in this class? or is it called from another class?

It's the static methods setInstrumenterAccess and setInstrumenterBuilderAccess

I realized that we could also add an @Initializer annotation to those methods - but we'd need a place to add this annotation.

See https://github.com/uber/NullAway/wiki/Supported-Annotations#initialization

oh, maybe it wants the static fields to be annotated with @Nullable

if we'd do that - we'd get an error when the field is accessed: instrumenterAccess.startAndEnd

I just added the annotation to see if that looks better