Sitecore Content Hub. Changing entity definition programmatically

Program.cs

using Stylelabs.M.Sdk.Models.Base;
using Stylelabs.M.Sdk.Models.Base.PropertyDefinitions;
using Stylelabs.M.Sdk.WebClient;
using Stylelabs.M.Sdk.WebClient.Authentication;
using System;
using System.Linq;
using System.Threading.Tasks;

namespace SchemaModification
{
    class Program
    {
        private static Random random = new Random();
        static async Task Main(string[] args)
        {
            Console.WriteLine("Hello World!");

            var client = CreateClient();

            var def = await client.EntityDefinitions.GetAsync("CNHI.Line");
            var mg = new MemberGroup();
            var name = $"Group{RandomString(4)}";
            mg.Name = name;

            var stringProperty = new StringPropertyDefinition()
            {
                Name = "Property1",
                
                // possible conditions.
                //Conditions = new List<IMemberCondition>() { new RelationMemberCondition() { } }
                //Conditions = new List<IMemberCondition>() { new BoolMemberCondition() { } }
                //Conditions = new List<IMemberCondition>() { new StringMemberCondition() { } }
                //Conditions = new List<IMemberCondition>() { new NoAncestorMemberCondition() { } }

            };
            
            mg.MemberDefinitions.Add(stringProperty);

            def.MemberGroups.Add(mg);

            var definition = await client.EntityDefinitions.SaveAsync(def);

            Console.WriteLine("Done");

            Console.ReadLine();
        }

        internal static IWebMClient CreateClient()
        {
            Uri endpoint = new Uri(Settings.ContentHub.ContentHubUrl);

            OAuthPasswordGrant oauth = new OAuthPasswordGrant
            {
                ClientId = Settings.ContentHub.ClientId,
                ClientSecret = Settings.ContentHub.ClientSecret,
                UserName = Settings.ContentHub.Username,
                Password = Settings.ContentHub.Password
            };

            IWebMClient client = MClientFactory.CreateMClient(endpoint, oauth);

            return client;
        }

        public static string RandomString(int length)
        {
            const string chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
            return new string(Enumerable.Repeat(chars, length)
              .Select(s => s[random.Next(s.Length)]).ToArray());
        }
    }
}