class_docstr: Add Prefix to src (& tgt) sentence.
docstr: Return str represent key arguments for class.
docstr_tok: ["Return","str","represent","key","arguments","for","class","."]
code: def _repr_args(self):
      """Return str represent key arguments for class."""
      return "{}={}".format("prefix_dict", self.prefix_dict)
  
imports: from onmt.utils.logging import logger
  from onmt.transforms import register_transform
  from .transform import Transform, ObservableStats
label_desc: Use image node_id 10 for calling the PrefixTransform obj's underlying member method code with example usage: obj._repr_args() and returns: str