Buffer
class Buffer extends Userdata<"fz_buffer"> { }
constructor();
constructor(data: string);
constructor(data: ArrayBuffer | Uint8Array);
constructor(pointer: Pointer<"fz_buffer">);
asString(): string;
asUint8Array(): Uint8Array;
getLength(): number;
readByte(at: number): number;
write(s: string): void;
writeBuffer(other: AnyBuffer): void;
writeByte(b: number): void;
writeLine(s: string): void;