class_docstr: Unit tests for the nearest neighbors builder class.
code: def test_author(self):
      builder = self.create_builder()
      self.assertIsNotNone(builder)
  
      self.assertEqual(builder.spec.description.metadata.author, "")
      builder.author = "John Doe"
      self.assertEqual(builder.author, "John Doe")
      self.assertEqual(
          builder.spec.description.metadata.author, "John Doe"
      )
  
imports: import os
  import shutil
  import unittest
  from coremltools._deps import _HAS_SKLEARN
  from coremltools.models import MLModel
  from coremltools.models.nearest_neighbors import KNearestNeighborsClassifierBuilder
  from coremltools.models.utils import _is_macos
label_desc: Use image node_id 7 for calling the NearestNeighborsBuilderTest obj's underlying member method code with example usage: obj.test_author() without return types