/// <summary>
 /// Adds the sub field.
 /// </summary>
 /// <param name="code">The code.</param>
 /// <param name="text">The text.</param>
 /// <returns>RecordField.</returns>
 public RecordField AddSubField
 (
     char code,
     string text
 )
 {
     SubFields.Add(new SubField(code, text));
     return(this);
 }
        /// <summary>
        /// Sets the sub field.
        /// </summary>
        /// <param name="code">The code.</param>
        /// <param name="text">The text.</param>
        /// <returns></returns>
        /// <remarks>Устанавливает значение только первого
        /// подполя с указанным кодом (если в поле их несколько)!
        /// </remarks>
        public RecordField SetSubField
        (
            char code,
            string text
        )
        {
            SubField subField = SubFields
                                .Find(_ => _.Code.SameChar(code));

            if (subField == null)
            {
                subField = new SubField(code, text);
                SubFields.Add(subField);
            }
            subField.Text = text;
            return(this);
        }