code: def colptr(self) -> torch.Tensor:
      colptr = self._colptr
      if colptr is not None:
          return colptr
  
      csr2csc = self._csr2csc
      if csr2csc is not None:
          colptr = torch.ops.torch_sparse.ind2ptr(
              self._col[csr2csc], self._sparse_sizes[1]
          )
      else:
          colptr = self._col.new_zeros(self._sparse_sizes[1] + 1)
          torch.cumsum(self.colcount(), dim=0, out=colptr[1:])
      self._colptr = colptr
      return colptr
  
imports: import warnings
  from typing import List, Optional, Tuple
  import torch
  from torch_scatter import scatter_add, segment_csr
  from torch_sparse.utils import Final, index_sort
label_desc: Use image node_id 19 for calling the SparseStorage obj's underlying member method code with example usage: obj.colptr() and returns: colptr, colptr