class MultipartWriterimport { MultipartWriter } from "https://deno.land/std@0.35.0/mime/mod.ts"; Writer for creating multipart/form-data ConstructorsnewMultipartWriter(writer: Writer, boundary?: string)Propertiesprivatereadonly_boundary: stringprivatebufWriter: BufWriterprivateisClosed: booleanprivatelastPart: PartWriter | undefinedreadonlyboundary: stringMethodsprivatecreatePart(headers: Headers): Writerprivateflush(): Promise<void>close(): Promise<void>Close writer. No additional data can be writen to stream createFormField(field: string): WritercreateFormFile(field: string, filename: string): WriterformDataContentType(): stringwriteField(field: string, value: string): Promise<void>writeFile(field: string,filename: string,file: Reader,): Promise<void>