var base64Data = btoa(reader.result);
var multipartRequestBody =
    delimiter +
    'Content-Type: application/json\r\n\r\n' +
    JSON.stringify(metadata) +
    delimiter +
    'Content-Type: ' + contentType + '\r\n' +
    'Content-Transfer-Encoding: base64\r\n' +
    '\r\n' +
    base64Data +
    close_delim;

var request = gapi.client.request({
    'path': '/upload/drive/v2/files',
    'method': 'POST',
    'params': {'uploadType': 'multipart'},
    'headers': {
      'Content-Type': 'multipart/mixed; boundary="' + boundary + '"'
    },
    'body': multipartRequestBody});
if (!callback) {
  callback = function(file) {
  };
}
request.execute(callback);

<h6>Saving a file</h6>
```javascript
function saveFile(fileId, content){
    //console.log(content);
    if(typeof content !== "undefined"){ //if nothing is "null"
        var contentArray = new Array(content.length);
        for (var i = 0; i < contentArray.length; i++) {
            contentArray[i] = content.charCodeAt(i);
        }
        var byteArray = new Uint8Array(contentArray);
        var blob = new Blob([byteArray], {type: 'text/plain'}); //this is the only way I could get this to work
        var request = gapi.client.drive.files.get({'fileId': fileId});//gets the metadata, which is left alone
        request.execute(function(resp) {
            //console.log(content);
            updateFile(fileId,resp,blob,changesSaved);
        });
    }
}
function updateFile(fileId, fileMetadata, fileData, callback) { //is the callback necessary?
  if(ok){
  const boundary = '-------314159265358979323846';
  const delimiter = "\r\n--" + boundary + "\r\n";
  const close_delim = "\r\n--" + boundary + "--";

  var reader = new FileReader();
  reader.readAsBinaryString(fileData);
  reader.onload = function(e) {
    var contentType = fileData.type || 'application/octet-stream';
    var base64Data = btoa(reader.result);
    //console.log(base64Data);
    var multipartRequestBody =
        delimiter +
        'Content-Type: application/json\r\n\r\n' +
        JSON.stringify(fileMetadata) +
        delimiter +
        'Content-Type: ' + contentType + '\r\n' +
        'Content-Transfer-Encoding: base64\r\n' +
        '\r\n' +
        base64Data +
        close_delim;

    var request = gapi.client.request({
        'path': '/upload/drive/v2/files/' + fileId,
        'method': 'PUT',
        'params': {'uploadType': 'multipart', 'alt': 'json'},
        'headers': {
          'Content-Type': 'multipart/mixed; boundary="' + boundary + '"'
        },
        'body': multipartRequestBody});
    if (!callback) {//this isn't necessary
      callback = function(file) {
        //console.log(file) //for some reason, this is important
      };
    }
    request.execute(callback);//not needed
  }
	}
}