public override bool Validate(out Dictionary <string, string> errors) { errors = new Dictionary <string, string>(); if (string.IsNullOrEmpty(ColumnName)) { errors.Add(nameof(ColumnName), "Column name is mandatory."); } if (ColumnName.HasTrailingSpaces()) { errors.Add(nameof(ColumnName), "Trailing spaces are not allowed."); } return(errors.Count == 0); }