code: def summary(self, featuresCol, weightCol=None):
          
          featuresCol, weightCol = Summarizer._check_param(featuresCol, weightCol)
          return Column(self._java_obj.summary(featuresCol._jc, weightCol._jc))
docs: Returns an aggregate object that contains the summary of the column with the requested
          metrics.
  
          :param featuresCol:
           a column that contains features Vector object.
          :param weightCol:
           a column that contains weight value. Default weight is 1.0.
          :return:
           an aggregate column that contains the statistics. The exact content of this
           structure is determined during the creation of the builder.