private File createZipWithMultipleExtensions() throws IOException {

		String zipName1 = "Foo";
		String zipName2 = "Bar";
		File externalFolder = createTempDirectory(BUILD_FOLDER_NAME);
		File f = new File(externalFolder, "MultiExtension.zip");
		try (ZipOutputStream out = new ZipOutputStream(new FileOutputStream(f))) {
			out.putNextEntry(new ZipEntry(zipName1 + "/"));
			out.putNextEntry(new ZipEntry(zipName1 + "/extension.properties"));

			out.putNextEntry(new ZipEntry(zipName2 + "/"));
			out.putNextEntry(new ZipEntry(zipName2 + "/extension.properties"));

			StringBuilder sb = new StringBuilder();
			sb.append("name:MultiExtension");
			byte[] data = sb.toString().getBytes();
			out.write(data, 0, data.length);
			out.closeEntry();
		}

		return f;
	}
Tests for the {@link ExtensionInstaller} class.
Ghidra/Framework/Project/src/test/java/ghidra/framework/project/extensions/ExtensionInstallerTest.java