code: def split(self, grouper):
          '''Split the current DenseRunVariable into multiple columns.
  
          Parameters
          ----------
          grouper : :obj:`pandas.DataFrame`
              Binary DF specifying the design matrix to use for splitting. Number
              of rows must match current ``DenseRunVariable``; a new ``DenseRunVariable``
              will be generated for each column in the grouper.
  
          Returns
          -------
          A list of DenseRunVariables, one per unique value in the grouper.
          '''
          values = grouper.values * self.values.values
          df = pd.DataFrame(values, columns=grouper.columns)
          return [DenseRunVariable(name='%s.%s' % (self.name, name),
                                   values=df[name].values,
                                   run_info=self.run_info,
                                   source=self.source,
                                   sampling_rate=self.sampling_rate)
                  for i, name in enumerate(df.columns)f split(self, grouper):
          '''Split the current DenseRunVariable into multiple columns.
  
          Parameters
          ----------
          grouper : :obj:`pandas.DataFrame`
              Binary DF specifying the design matrix to use for splitting. Number
              of rows must match current ``DenseRunVariable``; a new ``DenseRunVariable``
              will be generated for each column in the grouper.
  
          Returns
          -------
          A list of DenseRunVariables, one per unique value in the grouper.
          '''
          values = grouper.values * self.values.values
          df = pd.DataFrame(values, columns=grouper.columns)
          return [DenseRunVariable(name='%s.%s' % (self.name, name),
                                   values=df[name].values,
                                   run_info=self.run_info,
                                   source=self.source,
                                   sampling_rate=self.sampling_rate)
                  for i, name in enumerate(df.columns)]
docs: Split the current DenseRunVariable into multiple columns.
  
          Parameters
          ----------
          grouper : :obj:`pandas.DataFrame`
              Binary DF specifying the design matrix to use for splitting. Number
              of rows must match current ``DenseRunVariable``; a new ``DenseRunVariable``
              will be generated for each column in the grouper.
  
          Returns
          -------
          A list of DenseRunVariables, one per unique value in the grouper.