public static IList <Tree> getSeparators <T1>(ParserRuleContext ctx, IList <T1> siblings)
where T1 : Antlr4.Runtime.ParserRuleContext
{
ParserRuleContext first = siblings[0] as ParserRuleContext;
ParserRuleContext last = siblings[siblings.Count - 1] as ParserRuleContext;
int start = BuffUtils.indexOf(ctx, first);
int end = BuffUtils.indexOf(ctx, last);
IEnumerable <ITree> xxxx = Trees.GetChildren(ctx).Where((n, i) => i >= start && i < end + 1);
IList <Tree> elements = xxxx.ToList();
return(BuffUtils.filter(elements, c => c is TerminalNode));
}