code: def execute(cls, ctx, op: "DataFrameReadRayDataset"):
      out = op.outputs[0]
      ref = op.refs[0]
  
      df = ray.get(ref)
      ctx[out.key] = df
  
imports: import functools
  import warnings
  import numpy
  import pandas
  from ...None import opcodes
  from ...core import OutputType
  from ...serialization.serializables import AnyField, BoolField, ListField, Int64Field, ReferenceField
  from ..utils import parse_index, lazy_import, tokenize
  from .core import IncrementalIndexDatasource, IncrementalIndexDataSourceMixin, HeadOptimizedDataSource
label_desc: Use image node_id 3 for calling the DataFrameReadRayDataset obj's underlying member method code with example usage: obj.execute(cls, ctx, op) without return types