     {Number|dynamic} streams     - Quantity of parallel upload streams, default: 2
     {Number|dynamic} chunkSize   - Chunk size for upload
     {Function}    onUploaded     - Callback triggered when upload is finished, with two arguments `error` and `fileRef`
-    {Function}    onError        - Callback triggered on error in upload and/or FileReader, with two arguments `error` and `fileRef`
+    {Function}    onError        - Callback triggered on error in upload and/or FileReader, with two arguments `error` and `fileData`
     {Function}    onProgress     - Callback triggered when chunk is sent, with only argument `progress`
-    {Function}    onBeforeUpload - Callback triggered right before upload is started, with only `FileReader` argument:
-        context is `File` - so you are able to check for extension, mime-type, size and etc.
+    {Function}    onBeforeUpload - Callback triggered right before upload is started:
         return true to continue
         return false to abort upload
   @description Upload file to server over DDP

          unless EOFsent
            EOFsent = true
            opts =
              eof:       true
              meta:      config.meta
              file:      fileData
              fileId:    fileId
              binData:   'EOF'
              chunkId:    -1
              fileLength: fileLength
            Meteor.call self.methodNames.MeteorFileWrite, opts, end
          return

      _methods[self.methodNames.MeteorFileWrite] = (opts) ->
        @unblock()
        check opts, {
          eof:        Match.Optional Boolean
          meta:       Match.Optional Object
          file:       Object
          fileId:     String
          binData:    Match.Optional String
          chunkId:    Match.Optional Number
          fileLength: Number
        }

        opts.eof     ?= false
        opts.meta    ?= {}
        opts.binData ?= 'EOF'
        opts.chunkId ?= -1

        console.info "[Meteor.Files] [Write Method] Got ##{opts.chunkId}/#{opts.fileLength} chunks, dst: #{opts.file.name or opts.file.fileName}" if self.debug

