docs: public final String lookupSourceFile(@Nonnull @DottedClassName String dottedClassName) {
          requireNonNull(dottedClassName, "className is null");
          try {
              XClass xClass = Global.getAnalysisCache().getClassAnalysis(XClass.class,
                      DescriptorFactory.createClassDescriptorFromDottedClassName(dottedClassName));
              String name = xClass.getSource();
              if (name == null) {
                  return SourceLineAnnotation.UNKNOWN_SOURCE_FILE;
              }
              return name;
          } catch (CheckedAnalysisException e) {
              return SourceLineAnnotation.UNKNOWN_SOURCE_FILE;
          }
      }