docstr: Returns length penalty according to https://arxiv.org/pdf/1609.08144.pdf
docstr_tok: ["Returns","length","penalty","according","to","https",":","\/\/arxiv.org\/pdf\/1609.08144.pdf"]
code: def compute_len_penalty(lengths, alpha):
      """Returns length penalty according to https://arxiv.org/pdf/1609.08144.pdf"""
      return ((5 + lengths) / 6).pow(alpha)
  
imports: from contextlib import contextmanager
  import torch
  from nemo.collections.common.parts import NEG_INF, mask_padded_tokens
label_desc: Use image node_id 3 for calling the BeamSearchSequenceGeneratorWithLanguageModel obj's underlying member method code with example usage: obj.compute_len_penalty(lengths, alpha) and returns: unknown