code: def test_rounding(self):
      formatter = EngFormatter(accuracy=3, use_eng_prefix=True)
      in_out = [
          (5.55555, " 5.556"),
          (55.5555, " 55.556"),
          (555.555, " 555.555"),
          (5555.55, " 5.556k"),
          (55555.5, " 55.556k"),
          (555555, " 555.555k"),
      ]
      self.compare_all(formatter, in_out)
  
      formatter = EngFormatter(accuracy=1, use_eng_prefix=True)
      in_out = [
          (5.55555, " 5.6"),
          (55.5555, " 55.6"),
          (555.555, " 555.6"),
          (5555.55, " 5.6k"),
          (55555.5, " 55.6k"),
          (555555, " 555.6k"),
      ]
      self.compare_all(formatter, in_out)
  
      formatter = EngFormatter(accuracy=0, use_eng_prefix=True)
      in_out = [
          (5.55555, " 6"),
          (55.5555, " 56"),
          (555.555, " 556"),
          (5555.55, " 6k"),
          (55555.5, " 56k"),
          (555555, " 556k"),
      ]
      self.compare_all(formatter, in_out)
  
      formatter = EngFormatter(accuracy=3, use_eng_prefix=True)
      result = formatter(0)
      assert result == " 0.000"
  
file_path: pandas/pandas/tests/io/formats/test_eng_formatting.py
imports: import numpy
  import pytest
  from pandas import DataFrame, reset_option, set_eng_float_format
  from pandas.io.formats.format import EngFormatter
label_desc: Use image node_id 7 for calling the TestEngFormatter obj's underlying member method code with example usage: obj.test_rounding() without return types