newValue = newValue.plus(location);
                }
                return newValue;
            });
        }
    }

    public boolean shouldWatchLocation(String location) {
        return !locationsWrittenByCurrentBuild.get().contains(location);
    }

    public FileHierarchySet getImmutableLocations() {
        return immutableLocations;
    }

            this.delegate = delegate;
        }

        @Override
        public void handleChange(FileWatcherRegistry.Type type, Path path) {
            if (locationsWrittenByCurrentBuild.shouldWatchLocation(path.toString())) {
                delegate.handleChange(type, path);
            }
        }

        @Override
        public void stopWatchingAfterError() {