code: def test_regular_input(self):
      x = pd.Series(
          [
              "#hello #hi #hello",
              "#regular#expression#0or1#yes",
              "andorandorand #32309",
          ],
      )
      expected = [3.0, 0.0, 0.0]
      actual = self.primitive().get_function()(x)
      np.testing.assert_array_equal(actual, expected)
  
file_path: featuretools/featuretools/tests/primitive_tests/natural_language_primitives_tests/test_number_of_hashtags.py
imports: import numpy
  import pandas
  from featuretools.primitives import NumberOfHashtags
  from featuretools.tests.primitive_tests.utils import PrimitiveTestBase, find_applicable_primitives, valid_dfs
label_desc: Use image node_id 1 for calling the TestNumberOfHashtags obj's underlying member method code with example usage: obj.test_regular_input() without return types