code: public Nullness getNullness(TreePath exprPath, Context context) {
      try {
        nullnessPropagation.setContext(context).setCompilationUnit(exprPath.getCompilationUnit());
        return DataFlow.expressionDataflow(exprPath, context, nullnessPropagation);
      } finally {
        nullnessPropagation.setContext(null).setCompilationUnit(null);
      }
    }
docs: Returns the {@link Nullness} of the leaf of {@code exprPath}.
  
  <p>If the leaf required the compiler to generate autoboxing or autounboxing calls, {@code
  getNullness} returns the {@code Nullness} <i>after</i> the boxing/unboxing. This implies that,
  in those cases, it will always return {@code NONNULL}.