def filter_claim_fn(example, _):
  """Filter out claims/evidence that have zero length."""
  if 'claim_text_word_ids' in example:
    claim_length = len(example['claim_text_word_ids'])
  else:
    claim_length = len(example['claim_text'])

  # Explicit length check required.
  # Implicit length check causes TensorFlow to fail during tracing.
  if claim_length != 0:
    return True
  else:
    return False