code: def hist(self, dimension=None, num_bins=20, bin_range=None,
               adjoin=True, individually=True, **kwargs):
          
          if dimension is not None and not isinstance(dimension, list):
              dimension = [dimension]
          histmaps = [self.clone(shared_data=False) for _ in (dimension or [None])]
  
          if individually:
              map_range = None
          else:
              if dimension is None:
                  raise Exception("Please supply the dimension to compute a histogram for.")
              map_range = self.range(kwargs['dimension'])
  
          bin_range = map_range if bin_range is None else bin_range
          style_prefix = 'Custom[<' + self.name + '>]_'
          if issubclass(self.type, (NdOverlay, Overlay)) and 'index' not in kwargs:
              kwargs['index'] = 0
  
          for k, v in self.data.items():
              hists = v.hist(adjoin=False, dimension=dimension,
                             bin_range=bin_range, num_bins=num_bins,
                             style_prefix=style_prefix, **kwargs)
              if isinstance(hists, Layout):
                  for i, hist in enumerate(hists):
                      histmaps[i][k] = hist
              else:
                  histmaps[0][k] = hists
  
          if adjoin:
              layout = self
              for hist in histmaps:
                  layout = (layout << hist)
              if issubclass(self.type, (NdOverlay, Overlay)):
                  layout.main_layer = kwargs['index']
              return layout
          else:
              if len(histmaps) > 1:
                  return Layout(histmaps)
              else:
                  return histmaps[0]
docs: Computes and adjoins histogram along specified dimension(s).
  
          Defaults to first value dimension if present otherwise falls
          back to first key dimension.
  
          Args:
              dimension: Dimension(s) to compute histogram on
              num_bins (int, optional): Number of bins
              bin_range (tuple optional): Lower and upper bounds of bins
              adjoin (bool, optional): Whether to adjoin histogram
  
          Returns:
              AdjointLayout of HoloMap and histograms or just the
              histograms