dist/flow.js
function (preventEvents) {
      // In some cases (such as videos) it's really handy to upload the first
      // and last chunk of a file quickly; this let's the server check the file's
      // metadata and determine if there's even a point in continuing.
      var found = false;
      if (this.opts.prioritizeFirstAndLastChunk) {
        each(this.files, function (file) {
          if (!file.paused && file.chunks.length &&
            file.chunks[0].status() === 'pending') {
            file.chunks[0].send();
            found = true;
            return false;
          }
          if (!file.paused && file.chunks.length > 1 &&
            file.chunks[file.chunks.length - 1].status() === 'pending') {
            file.chunks[file.chunks.length - 1].send();
            found = true;
            return false;
          }
        });
        if (found) {
          return found;
        }
      }

      // Now, simply look for the next, best thing to upload
      each(this.files, function (file) {
        if (!file.paused) {
          each(file.chunks, function (chunk) {
            if (chunk.status() === 'pending') {
              chunk.send();
              found = true;
              return false;
            }
          });
        }
        if (found) {
          return false;
        }
      });
      if (found) {
        return true;
      }

      // The are no more outstanding chunks to upload, check is everything is done
      var outstanding = false;
      each(this.files, function (file) {
        if (!file.isComplete()) {
          outstanding = true;
          return false;
        }
      });
      if (!outstanding && !preventEvents) {
        // All chunks have been uploaded, complete
        async(function () {
          this.fire('complete');
        }, this);
      }
      return false;
    }
function (preventEvents) {
      // In some cases (such as videos) it's really handy to upload the first
      // and last chunk of a file quickly; this let's the server check the file's
      // metadata and determine if there's even a point in continuing.
      var found = false;
      if (this.opts.prioritizeFirstAndLastChunk) {
        each(this.files, function (file) {
          if (!file.paused && file.chunks.length &&
            file.chunks[0].status() === 'pending') {
            file.chunks[0].send();
            found = true;
            return false;
          }
          if (!file.paused && file.chunks.length > 1 &&
            file.chunks[file.chunks.length - 1].status() === 'pending') {
            file.chunks[file.chunks.length - 1].send();
            found = true;
            return false;
          }
        });
        if (found) {
          return found;
        }
      }

      // Now, simply look for the next, best thing to upload
      each(this.files, function (file) {
        if (!file.paused) {
          each(file.chunks, function (chunk) {
            if (chunk.status() === 'pending') {
              chunk.send();
              found = true;
              return false;
            }
          });
        }
        if (found) {
          return false;
        }
      });
      if (found) {
        return true;
      }

      // The are no more outstanding chunks to upload, check is everything is done
      var outstanding = false;
      each(this.files, function (file) {
        if (!file.isComplete()) {
          outstanding = true;
          return false;
        }
      });
      if (!outstanding && !preventEvents) {
        // All chunks have been uploaded, complete
        async(function () {
          this.fire('complete');
        }, this);
      }
      return false;
    }
Upload next chunk from the queue
@function
@returns {boolean}
@private