code: def to_bytes(value):
      
      if isinstance(value, text_type):
          return value.encode('utf-8')
      elif isinstance(value, ffi.CData):
          return ffi.string(value)
      elif isinstance(value, binary_type):
          return value
      else:
          raise ValueError('Value must be text, bytes, or char[]')
docs: Converts bytes, unicode, and C char arrays to bytes.
  
      Unicode strings are encoded to UTF-8.