code: def test_central_longitude(lon):
      eqearth = ccrs.EqualEarth(central_longitude=lon)
      other_args = {"ellps=WGS84", f"lon_0={lon}"}
      check_proj_params("eqearth", eqearth, other_args)
  
      assert_almost_equal(
          eqearth.x_limits,
          [-17243959.0622169, 17243959.0622169],
          decimal=5,
      )
      assert_almost_equal(
          eqearth.y_limits, [-8392927.59846646, 8392927.59846646]
      )
      # Expected aspect ratio from the paper.
      assert_almost_equal(
          np.diff(eqearth.x_limits) / np.diff(eqearth.y_limits),
          2.05458,
          decimal=5,
      )
  
file_path: cartopy/lib/cartopy/tests/crs/test_equal_earth.py
imports: import numpy
  from numpy.testing import assert_almost_equal
  import pytest
  import cartopy.crs
  from .helpers import check_proj_params
label_desc: Use image node_id 4 for calling a global function with example usage: test_central_longitude(lon) without return types