<PackageReference Include="Newtonsoft.Json" Version="11.0.2" />

Newtonsoft.Json.Utilities.StringBuffer

struct StringBuffer
Builds a string. Unlike StringBuilder this class lets you reuse its internal buffer.
namespace Newtonsoft.Json.Utilities { internal struct StringBuffer { public int Position { get; set; } public bool IsEmpty { get; } public char[] InternalBuffer { get; } public StringBuffer(IArrayPool<char> bufferPool, int initalSize); public void Append(IArrayPool<char> bufferPool, char value); public void Append(IArrayPool<char> bufferPool, char[] buffer, int startIndex, int count); public void Clear(IArrayPool<char> bufferPool); public string ToString(int start, int length); } }