private String getMD5(DomainFile file, Map<String, String> metadata) {
		return metadata.get(IndexType.MD5.metadataKey);
	}
@param indexType IndexType enum
@param mappingFunc bifunc that returns value that will be used to lookup the file
@param indexedFiles map of index keyvalue to fileId (either string or list of strings)
Ghidra/Features/Base/src/main/java/ghidra/plugin/importer/ProjectIndexService.java