code: def __str__(self) -> str:
      initial = (
          "MapInfo(size=UNKNOWN"
          if self.size == -1
          else "MapInfo(size=" + str(self.size)
      )
      return (
          initial
          + ",keyType="
          + self.key_type
          + ",valueType="
          + self.value_type
          + ")"
      )
  
imports: from abc import ABCMeta
  import sys
  from typing import Mapping, List
  from py4j import java_gateway
  from synapse.ml.onnx._ONNXModel import _ONNXModel
  from pyspark.ml.common import inherit_doc
  from py4j.java_gateway import JavaObject
label_desc: Use image node_id 3 for calling the MapInfo obj's underlying member method code with example usage: obj.__str__() and returns: unknown