code: def test_span_maker_forward_with_empty():
      """The forward pass of the span maker may have a doc with no entities."""
      nlp = English()
      doc1 = nlp("a b c")
      ent = doc1[0:1]
      ent.label_ = "X"
      doc1.ents = [ent]
      # no entities
      doc2 = nlp("x y z")
  
      # just to get a model
      span_maker = build_span_maker()
      span_maker([doc1, doc2], False)
  
imports: from typing import Any, Callable, Dict, Iterable, Tuple
  import pytest
  from numpy.testing import assert_equal
  from spacy import Language, registry, util
  from spacy.attrs import ENT_KB_ID
  from spacy.compat import pickle
  from spacy.kb import Candidate, InMemoryLookupKB, KnowledgeBase, get_candidates
  from spacy.lang.en import English
  from spacy.ml import load_kb
  from spacy.ml.models.entity_linker import build_span_maker
  from spacy.pipeline import EntityLinker
  from spacy.pipeline.legacy import EntityLinker_v1
  from spacy.pipeline.tok2vec import DEFAULT_TOK2VEC_MODEL
  from spacy.scorer import Scorer
  from spacy.tests.util import make_tempdir
  from spacy.tokens import Doc, Span
  from spacy.training import Example
  from spacy.util import ensure_path
  from spacy.vocab import Vocab
label_desc: Use image node_id 42 for calling a global function with example usage: test_span_maker_forward_with_empty() without return types