class_docstr: Tests specific to IntervalIndex.from_breaks
docstr: breaks of length one produce an empty IntervalIndex
docstr_tok: ["breaks","of","length","one","produce","an","empty","IntervalIndex"]
code: def test_length_one(self):
      """breaks of length one produce an empty IntervalIndex"""
      breaks = [0]
      result = IntervalIndex.from_breaks(breaks)
      expected = IntervalIndex.from_breaks([])
      tm.assert_index_equal(result, expected)
  
imports: from functools import partial
  import numpy
  import pytest
  import pandas.util._test_decorators
  from pandas.core.dtypes.common import is_unsigned_integer_dtype
  from pandas.core.dtypes.dtypes import IntervalDtype
  from pandas import Categorical, CategoricalDtype, CategoricalIndex, Index, Interval, IntervalIndex, date_range, notna, period_range, timedelta_range
  import pandas._testing
  from pandas.core.arrays import IntervalArray
  import pandas.core.common
label_desc: Use image node_id 4 for calling the TestFromBreaks obj's underlying member method code with example usage: obj.test_length_one() without return types