async blob() {
        const data = await fs.promises.readFile(this.filePath);
        return new Blob([data], { type: this.headers.get('content-type') });
    }
Reads the contents of the file specified by the filePath property and returns a Promise that
resolves with a Blob containing the file's contents.
@returns {Promise<Blob>} A Promise that resolves with a Blob containing the file's contents.
@throws {Error} If the file cannot be read.