docstr: A proxy-call to the dataframe's `.median()`.
code: def median(self):
      """
      A proxy-call to the dataframe's `.median()`.
      """
      return self.dataframe.median()
  
imports: from abc import ABC
label_desc: Use image node_id 29 for calling the DataframeAbstract obj's underlying member method code with example usage: obj.median() and returns: self