Как перевести requestBody.raw в строку или же в объект?

function arrayBufferToString(buffer){
    var byteArray = new Uint8Array(buffer);
    var str = "", cc = 0, numBytes = 0;
    for(var i=0, len = byteArray.length; i<len; ++i){
        var v = byteArray[i];
        if(numBytes > 0){
            //2 bit determining that this is a tailing byte + 6 bit of payload
            if((cc&192) === 192){
                //processing tailing-bytes
                cc = (cc << 6) | (v & 63);
            }else{
                throw new Error("this is no tailing-byte");
            }
        }else if(v < 128){
            //single-byte
            numBytes = 1;
            cc = v;
        }else if(v < 192){
            //these are tailing-bytes
            throw new Error("invalid byte, this is a tailing-byte")
        }else if(v < 224){
            //3 bits of header + 5bits of payload
            numBytes = 2;
            cc = v & 31;
        }else if(v < 240){
            //4 bits of header + 4bit of payload
            numBytes = 3;
            cc = v & 15;
        }else{
            //UTF-8 theoretically supports up to 8 bytes containing up to 42bit of payload
            //but JS can only handle 16bit.
            throw new Error("invalid encoding, value out of range")
        }

        if(--numBytes === 0){
            str += String.fromCharCode(cc);
        }
    }
    if(numBytes){
        throw new Error("the bytes don't sum up");
    }
    return str;
}