@Override
	public DataType toDataType() throws DuplicateNameException, IOException {
		StructureDataType struct = new StructureDataType(getStructureName(), 0);
		struct.add(super.toDataType(), super.getStructureName(), "");
		struct.add(DWORD, "NumFields",
			"The number of stored properties in the struct. If there is a field offset vector, this is its length.");
		struct.add(DWORD, "FieldOffsetVectorOffset",
			"The offset of the field offset vector for this struct's stored properties in its metadata, if any. 0 means there is no field offset vector.");
		struct.setCategoryPath(new CategoryPath(DATA_TYPE_CATEGORY));
		return struct;
	}
Gets the offset of the field offset vector for this struct's stored properties in its 
metadata, if any. 0 means there is no field offset vector.

@return The offset of the field offset vector for this struct's stored properties in its 
  metadata, if any. 0 means there is no field offset vector.
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/swift/types/TargetStructDescriptor.java