code: def test_format_unhashed_feature():
      assert format_unhashed_feature([]) == ""
      assert (
          format_unhashed_feature([{"name": "foo", "sign": 1}]) == "foo"
      )
      assert (
          format_unhashed_feature([{"name": "foo", "sign": -1}])
          == "(-)foo"
      )
      assert (
          format_unhashed_feature(
              [{"name": "foo", "sign": 1}, {"name": "bar", "sign": -1}]
          )
          == 'foo <span title="(-)bar">&hellip;</span>'
      )
      assert (
          format_unhashed_feature(
              [
                  {"name": "foo", "sign": 1},
                  {"name": "bar", "sign": -1},
                  {"name": "boo", "sign": 1},
              ]
          )
          == 'foo <span title="(-)bar\nboo">&hellip;</span>'
      )
  
imports: import re
  import pytest
  import numpy
  from sklearn.datasets import make_regression
  from sklearn.linear_model import LinearRegression
  from eli5.base import DocWeightedSpans, FeatureWeight
  from eli5 import explain_weights_sklearn, explain_prediction_sklearn
  from eli5.formatters import format_as_text, format_as_html, format_html_styles, FormattedFeatureName
  from eli5.formatters.html import _format_unhashed_feature, render_weighted_spans, _format_single_feature, _format_feature, remaining_weight_color_hsl, weight_color_hsl
  from eli5.formatters.text_helpers import get_char_weights, PreparedWeightedSpans
  from .utils import write_html
label_desc: Use image node_id 6 for calling a global function with example usage: test_format_unhashed_feature() without return types