public ZipBuilder addFolder(final String folderName) throws IOException {
		ZipUtil.addFolderToZip(zos, folderName, null);
		return this;
	}
public ZipBuilder addFolder(final String folderName) throws IOException {
		ZipUtil.addFolderToZip(zos, folderName, null);
		return this;
	}
public ZipBuilder addFolder ( final String folderName ) throws IOException { ZipUtil . addFolderToZip ( zos , folderName , null ) ; return this ; }
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