Forecasting Hierarchical Time Series Using Information Combination // Implements the Information Combination (IComb) approach proposed by Nguyen, Vahid and Wickramasuriya (2025)htt ps://www.monash.edu/business/ebs/research/publications/ebs/2025 /wp11-2025.pdf for hierarchical forecast reconciliation. The method combines information from base forecasts constructed using different information sets while ensuring coherence. It is implemented using a penalized regression-based framework.