code: def execute(cls, ctx, op: "DataFrameMelt"):
      in_data = ctx[op.inputs[0].key]
      ctx[op.outputs[0].key] = in_data.melt(
          id_vars=op.id_vars,
          value_vars=op.value_vars,
          var_name=op.var_name,
          value_name=op.value_name,
          col_level=op.col_level,
      )
  
imports: import numpy
  import pandas
  from ...None import opcodes
  from ...core import recursive_tile
  from ...serialization.serializables import AnyField, StringField
  from ...utils import calc_nsplits
  from ..operands import DataFrameOperand, DataFrameOperandMixin, OutputType
  from ..utils import build_empty_df, parse_index, standardize_range_index
label_desc: Use image node_id 9 for calling the DataFrameMelt obj's underlying member method code with example usage: obj.execute(cls, ctx, op) without return types