in log4j-weaver/src/main/java/org/apache/logging/log4j/weaver/LocationCacheGenerator.java [213:221]
public static Path getCacheClassFile(final Path classFile) {
final Path fileName = classFile.getFileName();
if (fileName == null) {
throw new IllegalArgumentException("The 'classFile' parameter is an empty path.");
}
final String cacheFileName = LocationCacheGenerator
.getCacheClassName(StringUtils.removeEnd(fileName.toString(), ".class")) + ".class";
return classFile.resolveSibling(cacheFileName);
}