@Override
	public DataType toDataType() throws DuplicateNameException, IOException {
		DataType annotationDataType = annotation.toDataType();

		StringBuilder builder = new StringBuilder();
		builder.append("annotation_item" + "_");
		builder.append(visibility + "_");
		builder.append(annotationDataType.getName());

		Structure structure = new StructureDataType(builder.toString(), 0);
		structure.add(BYTE, "visibility", null);
		structure.add(annotationDataType, "annotation", null);

		builder.append(structure.getLength() + "_");

		structure.setCategoryPath(new CategoryPath("/dex/annotation_item"));
		try {
			structure.setName(builder.toString());
		}
		catch (Exception e) {
			// ignore
		}
		return structure;
	}
https://android.googlesource.com/platform/art/+/master/libdexfile/dex/dex_file_structs.h
Ghidra/Features/FileFormats/src/main/java/ghidra/file/formats/android/dex/format/AnnotationItem.java