code: def _index_tensor(x: Tensor, item: Any) -> Tensor:
      squeeze: List[int] = []
      if not isinstance(item, tuple):
          item = (item,)
  
      saw_ellipsis = False
  
      for i, item_i in enumerate(item):
          axis = i - len(item) if saw_ellipsis else i
          if isinstance(item_i, int):
              if item_i != -1:
                  x = x.slice_axis(
                      axis=axis, begin=item_i, end=item_i + 1
                  )
              else:
                  x = x.slice_axis(axis=axis, begin=-1, end=None)
              squeeze.append(axis)
          elif item_i == slice(None):
              continue
          elif item_i == Ellipsis:
              saw_ellipsis = True
              continue
          elif isinstance(item_i, slice):
              assert item_i.step is None
              start = item_i.start if item_i.start is not None else 0
              x = x.slice_axis(axis=axis, begin=start, end=item_i.stop)
          else:
              raise RuntimeError(f"invalid indexing item: {item}")
      if len(squeeze):
          x = x.squeeze(axis=tuple(squeeze))
      return x
  
imports: from typing import cast, Any, List, Optional, Tuple
  import mxnet
  import numpy
  from mxnet import autograd
  from gluonts.mx import Tensor
label_desc: Use image node_id 4 for calling a global function with example usage: _index_tensor(x, item) and returns: x