code: def flat_strip(tokens, tokenizer, return_indices=False):
      return (
          tokenizer.convert_tokens_to_string(tokens)
          .replace(" ", "")
          .lower()
      )
  
imports: from jiant.tasks.utils import ExclusiveSpan
label_desc: Use image node_id 4 for calling a global function with example usage: flat_strip(tokens, tokenizer, return_indices) and returns: tokenizer