public FunctionRecord getFunctionByID(long functionID) {
		for (FidDB fidDb : fidDbList) {
			FunctionRecord functionRecord = fidDb.getFunctionByID(functionID);
			if (functionRecord != null) {
				return functionRecord;
			}
		}
		return null;
	}
Returns a single function record given its id, or null if no such record exists,
searching across all attached databases.
NOTE: function record ids are generated so they are unique across libraries and
databases.
@param functionID the function record primary key id
@return the function record or null if non-existent
Ghidra/Features/FunctionID/src/main/java/ghidra/feature/fid/db/FidQueryService.java