docstr: A proxy-call to the dataframe's `.notna()`.
code: def notna(self):
      """
      A proxy-call to the dataframe's `.notna()`.
      """
      return self.dataframe.notna()
  
imports: from abc import ABC
label_desc: Use image node_id 12 for calling the DataframeAbstract obj's underlying member method code with example usage: obj.notna() and returns: self