Pihrtsoft.Text.RegularExpressions.Linq.Chars.Underscore C# (CSharp) Method

        public static CharGrouping Underscore() => Character(AsciiChar.Underscore);

 /// <summary>
 /// Appends a pattern that matches an underscore.
 /// </summary>
 /// <returns></returns>
 public CharGrouping Underscore() => Append(Chars.Underscore());