@Override
	public DomainFile getFileByID(String fileID) {
		return fileIndex.getFileByID(fileID);
	}
Returns the owner of the project that is associated with this 
DefaultProjectData.  A value of null indicates an old multiuser
project.
@return the owner of the project
Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DefaultProjectData.java