code: def asarray(self, key=None, series=None):
          
          if key is None and series is None:
              series = 0
          if series is not None:
              pages = self.series[series].pages
          else:
              pages = self.pages
  
          if key is None:
              pass
          elif isinstance(key, int):
              pages = [pages[key]]
          elif isinstance(key, slice):
              pages = pages[key]
          elif isinstance(key, collections.Iterable):
              pages = [pages[k] for k in key]
          else:
              raise TypeError('key must be an int, slice, or sequence')
  
          if len(pages) == 1:
              return pages[0].asarray()
          elif self.is_nih:
              result = numpy.vstack(p.asarray(colormapped=False,
                                              squeeze=False) for p in pages)
              if pages[0].is_palette:
                  result = numpy.take(pages[0].color_map, result, axis=1)
                  result = numpy.swapaxes(result, 0, 1)
          else:
              if self.is_ome and any(p is None for p in pages):
                  firstpage = next(p for p in pages if p)
                  nopage = numpy.zeros_like(
                      firstpage.asarray())
              result = numpy.vstack((p.asarray() if p else nopage)
                                    for p in pages)
          if key is None:
              try:
                  result.shape = self.series[series].shape
              except ValueError:
                  warnings.warn("failed to reshape %s to %s" % (
                                result.shape, self.series[series].shape))
                  result.shape = (-1,) + pages[0].shape
          else:
              result.shape = (-1,) + pages[0].shape
          return result
docs: Return image data of multiple TIFF pages as numpy array.
  
          By default the first image series is returned.
  
          Parameters
          ----------
          key : int, slice, or sequence of page indices
              Defines which pages to return as array.
          series : int
              Defines which series of pages to return as array.