class_docstr: A simple converter class that serializes/deserializes a string.
code: def deserialize_payload_from_stream(self, stream: IO) -> object:
      return stream.read().decode()
  
imports: from __future__ import absolute_import
  import pytest
  from io import BytesIO
  from typing import IO
  import numpy
  from pandas import DataFrame
  from sagemaker.serve import SchemaBuilder, CustomPayloadTranslator
  from sagemaker.serve.builder.schema_builder import JSONSerializerWrapper, CSVSerializerWrapper
  from sagemaker.deserializers import BytesDeserializer, NumpyDeserializer, JSONDeserializer, PandasDeserializer
  from sagemaker.serializers import DataSerializer, NumpySerializer
label_desc: Use image node_id 2 for calling the MyPayloadTranslator obj's underlying member method code with example usage: obj.deserialize_payload_from_stream(stream) and returns: stream