Antlr4.Tool.LeftRecursionCyclesMessage.GetStartTokenOfFirstRule C# (CSharp) Method

        protected static IToken GetStartTokenOfFirstRule(IEnumerable<IEnumerable<Rule>> cycles)
        {
            if (cycles == null)
            {
                return null;
            }

            foreach (IEnumerable<Rule> collection in cycles)
            {
                if (collection == null)
                {
                    return null;
                }

                foreach (Rule rule in collection)
                {
                    if (rule.ast != null)
                    {
                        return rule.ast.Token;
                    }
                }
            }
            return null;
        }
    }