class_docstr: The DummySequenceDescriptor is an empty object that allows us to perform schedulability
  checks before formally tracking a sequence.
class_docstr_tok: ["The","DummySequenceDescriptor","is","an","empty","object","that","allows","us","to","perform","schedulability","checks","before","formally","tracking","a","sequence","."]
code: def __init__(
      self, seen_tokens=0, cur_allocated_blocks=0, kv_blocks_ptr=0
  ) -> None:
      self._seen_tokens = seen_tokens
      self._cur_allocated_blocks = cur_allocated_blocks
      self._kv_blocks_ptr = kv_blocks_ptr
  
imports: from typing import List, Tuple, Union
  import torch
label_desc: Use image node_id 1 to create a new PlaceholderSequenceDescriptor object from inherited base classes: BaseSequenceDescriptor with example: obj = PlaceholderSequenceDescriptor(seen_tokens, cur_allocated_blocks, kv_blocks_ptr)