@Override
	public Category getCategory(long id) {
		lock.acquire();
		try {
			return getCategoryDB(id);
		}
		catch (IOException e) {
			dbError(e);
			return null;
		}
		finally {
			lock.release();
		}
	}
Get the category for the given ID.

@return null if no category exists with the given ID.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/data/DataTypeManagerDB.java