Constraint handling is not necessarily an integral component of a specific metaheuristic but rather a general technique that can be incorporated into any algorithm, including metaheuristics, to address constraints effectively. There are various strategies to handle non-linear equality constraints, such as penalty functions, repair methods, decoders, or multi-objective approaches, which can be adapted based on the problem context and the chosen algorithm.
For a deeper understanding of how to handle constraints in optimization, I recommend reviewing the following papers:
Chapter How to Handle Constraints with Evolutionary Algorithms
Article A Review on Constraint Handling Techniques for Population-ba...