docstr: A proxy-call to the dataframe's `.filter()`.
code: def filter(self, expr):
      """
      A proxy-call to the dataframe's `.filter()`.
      """
      return self.dataframe.filter(items=expr)
  
imports: from abc import ABC
label_desc: Use image node_id 53 for calling the DataframeAbstract obj's underlying member method code with example usage: obj.filter(expr) and returns: self