Optional format
format?: "image/png" | "pdf" | "svg" | "application/pdf" | "png" | "jpg" | "image/jpg" | "image/svg+xml" | `image/png@${number}x` | `pdf@${number}x` | `svg@${number}x` | `application/pdf@${number}x` | `png@${number}x` | `jpg@${number}x` | `image/jpg@${number}x` | `image/svg+xml@${number}x`
The image format to use.