code: def test_binwidth(self, long_df):
      binwidth = 0.5
      h = Hist(binwidth=binwidth)
      bin_kws = h._define_bin_params(long_df, "x", "continuous")
      n_bins = bin_kws["bins"]
      left, right = bin_kws["range"]
      assert (right - left) / n_bins == pytest.approx(binwidth)
  
imports: import numpy
  import pandas
  import pytest
  from numpy.testing import assert_array_equal
  from seaborn._core.groupby import GroupBy
  from seaborn._stats.counting import Hist, Count
label_desc: Use image node_id 6 for calling the TestHist obj's underlying member method code with example usage: obj.test_binwidth(long_df) without return types