public ArrayRun Append(int elementCount) { var lastArrayCharacterIndex = FormatString.LastIndexOf(ArrayEnd); var newFormat = FormatString.Substring(0, lastArrayCharacterIndex + 1); if (newFormat != FormatString) { newFormat += ElementCount + elementCount; } return(new ArrayRun(owner, newFormat, LengthFromAnchor, Start, ElementCount + elementCount, ElementContent, PointerSources, PointerSourcesForInnerElements)); }