docs: @Nonnull
      public SourceLineAnnotation getPrimarySourceLineAnnotation() {
          // Highest priority: return the first top level source line annotation
          for (BugAnnotation annotation : annotationList) {
              if (annotation instanceof SourceLineAnnotation
                      && SourceLineAnnotation.DEFAULT_ROLE.equals(annotation.getDescription())
                      && !((SourceLineAnnotation) annotation).isUnknown()) {
                  return (SourceLineAnnotation) annotation;
              }
          }
  
          for (BugAnnotation annotation : annotationList) {
              if (annotation instanceof SourceLineAnnotation && !((SourceLineAnnotation) annotation).isUnknown()) {
                  return (SourceLineAnnotation) annotation;
              }
          }
          // Next: Try primary method, primary field, primary class
          SourceLineAnnotation srcLine;
          if ((srcLine = inspectPackageMemberSourceLines(getPrimaryMethod())) != null) {
              return srcLine;
          }
          if ((srcLine = inspectPackageMemberSourceLines(getPrimaryField())) != null) {
              return srcLine;
          }
          if ((srcLine = inspectPackageMemberSourceLines(getPrimaryClass())) != null) {
              return srcLine;
          }
  
          // Last resort: throw exception
          throw new IllegalStateException("BugInstance for " + getType()
                  + " must contain at least one class, method, or field annotation");
      }