class_docstr: Provide test coverage when using provided estimators for optimal number of
  bins
class_docstr_tok: ["Provide","test","coverage","when","using","provided","estimators","for","optimal","number","of","bins"]
code: def test_signed_integer_data(self, bins):
      # Regression test for gh-14379.
      a = np.array([-2, 0, 127], dtype=np.int8)
      hist, edges = np.histogram(a, bins=bins)
      hist32, edges32 = np.histogram(a.astype(np.int32), bins=bins)
      assert_array_equal(hist, hist32)
      assert_array_equal(edges, edges32)
  
imports: import numpy
  from numpy.lib.histograms import histogram, histogramdd, histogram_bin_edges
  from numpy.testing import assert_, assert_equal, assert_array_equal, assert_almost_equal, assert_array_almost_equal, assert_raises, assert_allclose, assert_array_max_ulp, assert_raises_regex, suppress_warnings
  from numpy.testing._private.utils import requires_memory
  import pytest
label_desc: Use image node_id 10 for calling the TestHistogramOptimBinNums obj's underlying member method code with example usage: obj.test_signed_integer_data(bins) without return types