code: def CreateByteVector(self, x):
          
  
          self.assertNotNested()
          ## @cond FLATBUFFERS_INTERNAL
          self.nested = True
          ## @endcond
  
          if not isinstance(x, compat.binary_types):
              raise TypeError("non-byte vector passed to CreateByteVector")
  
          self.Prep(N.UOffsetTFlags.bytewidth, len(x)*N.Uint8Flags.bytewidth)
  
          l = UOffsetTFlags.py_type(len(x))
          ## @cond FLATBUFFERS_INTERNAL
          self.head = UOffsetTFlags.py_type(self.Head() - l)
          ## @endcond
          self.Bytes[self.Head():self.Head()+l] = x
  
          return self.EndVector(len(x))
docs: CreateString writes a byte vector.