public synchronized GFile getFileByIndex(long fileIndex) {
		FileData<METADATATYPE> fileData = fileIndexToEntryMap.get(fileIndex);
		return (fileData != null) ? fileData.file : null;
	}
Gets the GFile instance that was associated with the filesystem file index.

@param fileIndex index of the file in its filesystem
@return the associated GFile instance, or null if not found
Ghidra/Features/Base/src/main/java/ghidra/formats/gfilesystem/FileSystemIndexHelper.java