DependencyCollection.cs

using System.Collections;
using System.Collections.Generic;

namespace UnityEditor.ShaderGraph
{
    [GenerationAPI]
    internal class DependencyCollection : IEnumerable<DependencyCollection.Item>
    {
        public class Item
        {
            public FieldDependency dependency { get; }

            public Item(FieldDependency dependency)
            {
                this.dependency = dependency;
            }
        }

        readonly List<DependencyCollection.Item> m_Items;

        public DependencyCollection()
        {
            m_Items = new List<DependencyCollection.Item>();
        }

        public DependencyCollection Add(DependencyCollection dependencies)
        {
            m_Items.AddRange(dependencies);

            return this;
        }

        public DependencyCollection Add(FieldDependency dependency)
        {
            m_Items.Add(new Item(dependency));
            return this;
        }

        public IEnumerator<DependencyCollection.Item> GetEnumerator()
        {
            return m_Items.GetEnumerator();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }
    }
}