C# DisjointSet implementation (UnionFind)

DisjointSet.cs

using System.Collections.Generic;

public class DisjointSet<T>
{
    Dictionary<T, T> parents = new Dictionary<T, T>();
    Dictionary<T, int> weights = new Dictionary<T, int>();

    public T Union(T a, T b) {
        var aParent = Find(a);
        var bParent = Find(b);

        if (weights[aParent] >= weights[bParent]) {
            parents[bParent] = aParent;
            return aParent;
        }
        else {
            parents[aParent] = bParent;
            return bParent;
        }
    }

    public T Find(T child, bool createIfNotExist = true, bool compressPaths = true)
    {
        if (parents.TryGetValue(child, out var parent)) {
            if (!child.Equals(parent)) {
                parent = Find(parent, createIfNotExist, compressPaths);
                if (compressPaths) {
                    var oldParent = parents[child];
                    weights[oldParent]--;
                    parents[child] = parent;
                    weights[parent]++;
                }
            }
            return parent;
        }
        if (createIfNotExist) {
            parents[child] = child;
            weights[child] = 0;
        }
        return child;
    }

    public IEnumerable<T> GetRootValues() {
        foreach (var kvp in parents)
        {
            if (kvp.Key.Equals(kvp.Value)) {
                yield return kvp.Key;
            }
        }
    }
}