in log4j-weaver/src/main/java/org/apache/logging/log4j/weaver/LocationCacheGenerator.java [59:66]
public LocationCacheValue addLocation(final String internalClassName, final String methodName,
final String fileName, final int lineNumber) {
final String cacheClassName = getCacheClassName(internalClassName);
final LocationCacheContents contents = locationCacheClasses.computeIfAbsent(cacheClassName,
k -> new LocationCacheContents());
final int index = contents.addLocation(internalClassName, methodName, fileName, lineNumber);
return new LocationCacheValue(cacheClassName, LOCATION_FIELD, index);
}