code: def n(self):
      return self._n
  
file_path: mars/mars/tensor/fft/rfftfreq.py
imports: import numpy
  from ...None import opcodes
  from ...core import recursive_tile
  from ...serialization.serializables import Int32Field, Float64Field
  from ..datasource import arange
  from ..operands import TensorOperand, TensorOperandMixin
  from ..core import TensorOrder
label_desc: Use image node_id 2 for calling the TensorRFFTFreq obj's underlying member method code with example usage: obj.n() and returns: self